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Fiber and Functional Gastrointestinal Disorders


Abstract and Figures

Despite years of advising patients to alter their dietary and supplementary fiber intake, the evidence surrounding the use of fiber for functional bowel disease is limited. This paper outlines the organization of fiber types and highlights the importance of assessing the fermentation characteristics of each fiber type when choosing a suitable strategy for patients. Fiber undergoes partial or total fermentation in the distal small bowel and colon leading to the production of short-chain fatty acids and gas, thereby affecting gastrointestinal function and sensation. When fiber is recommended for functional bowel disease, use of a soluble supplement such as ispaghula/psyllium is best supported by the available evidence. Even when used judiciously, fiber can exacerbate abdominal distension, flatulence, constipation, and diarrhea.Am J Gastroenterol advance online publication, 2 April 2013; doi:10.1038/ajg.2013.63.
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The American Journal of GASTROENTEROLOGY VOLUME 108 | MAY 2013
ROME FOUNDATION WORKING GROUP nature publishing group
see related editorial on page x
Fiber has long been used for the treatment of various gastroin-
testinal and non-gastrointestinal conditions including constipa-
tion ( 1 – 4 ), diarrhea ( 5 – 12 ), ulcerative colitis ( 13 – 15 ), obesity in
children and adolescents ( 16,17 ), hypercholesterolemia ( 18 – 23 ),
and diabetes mellitus ( 22,24,25 ).  e National Academy of
Sciences Institute of Medicine recommends that adults consume
20 – 35 g of dietary ber per day, but the average American s daily
intake of dietary  ber is only 12 – 18 g ( 26 ). Although a univer-
sally accepted de nition for dietary  ber does not exist, it is gen-
erally agreed that this term includes carbohydrates that are not
hydrolyzed or absorbed in the upper part of the gastrointestinal
tract. For the purpose of communicating nutrition information
to the consumer, the term dietary  ber is of great value because it
clearly distinguishes between this non-digestible class of carbohy-
drates and digestible, glycemic carbohydrates such as sugars and
starches. Despite the confusing terminology surrounding the dif-
ferent  ber types, the term dietary  ber has been useful in nutri-
tion education and product development. In nutritional labeling,
ber is typically listed as a single category and not broken down
into soluble or insoluble subtypes.
Fiber metabolism
Dietary ber has a major role in the gastrointestinal tract
( Figure 1 ). Any undigested carbohydrate that reaches the colon
will be fermented (partly or totally) by the gut bacteria to produce
short-chain fatty acids (SCFAs) and a number of gases, including
carbon dioxide, hydrogen, and methane ( 27,28 ). SCFAs (mainly
acetate, propionate, and butyrate) in turn create an osmotic load,
are absorbed, and are further metabolized by colonocytes, hepato-
cytes, or the peripheral tissues ( 29 – 31 ). e fermentation of  ber
also in uences fecal bulking in an indirect manner as fermentation
by colonic micro ora stimulates growth and results in increased
microbial biomass ( 32 ).  us, the type of  ber consumed leads to
adaptation of, and changes to, the microbiome. Dietary  ber can
also in uence bulking directly via water retention ( 3,33,34 ).  e
unwanted side-e ect of  ber ingestion and subsequent fermenta-
tion, however, is the production of gas.  is gas is o en malodor-
ous and may in turn cause undesirable discomfort, bloating, and
atus in many individuals.  is characteristic of many  ber types
may be particularly relevant for those with functional gastrointes-
tinal disorders.
Types of fi ber
e fermentability and solubility of di erent “  ber ” types relates
closely to their chemical composition (e.g., presence of cellu-
lose, hemicellulose, gums, resistant starch, lignins, pectins).
For the purpose of this review,  ber will be broadly divided
into short chain- and long- chain carbohydrates or  ber-types,
based on their solubility and fermentation characteristics
( Tab l e 1 ( 35 – 38 )). Short chain carbohydrates or ber includes
the oligosaccharides: fructo-oligosaccharides and galacto-
oligosaccharides (e.g., ra nose and stachyose). Owing to their
size and solubility, both fructo-oligosaccharides and galacto-
oligosaccharide  bers are highly fermentable.  e long-chain
carbohydrates include four major groups: (1) soluble, highly
fermentable non-starch polysaccharide  ber (e.g., resistant
starch, pectin, inulin, guar gum); (2) intermediate soluble and
fermentable  ber (psyllium / ispaghula) and oats; (3) insoluble,
slowly fermentable  ber (wheat bran, lignin ( ax), and fruits
and vegetables); and  nally (4) insoluble, non-fermentable  ber
(cellulose, sterculia, and methycelullose).
Fiber and Functional Gastrointestinal Disorders
Shanti Eswaran , MD
1 , Jane Muir , PhD
2 and William D. Chey , MD, AGAF, FACG, FACP
Despite years of advising patients to alter their dietary and supplementary fi ber intake, the evidence surrounding the
use of fi ber for functional bowel disease is limited. This paper outlines the organization of fi ber types and highlights
the importance of assessing the fermentation characteristics of each fi ber type when choosing a suitable strategy for
patients. Fiber undergoes partial or total fermentation in the distal small bowel and colon leading to the production of
short-chain fatty acids and gas, thereby affecting gastrointestinal function and sensation. When fi ber is recommended
for functional bowel disease, use of a soluble supplement such as ispaghula / psyllium is best supported by the
available evidence. Even when used judiciously, fi ber can exacerbate abdominal distension, fl atulence, constipation,
and diarrhea.
Am J Gastroenterol 2013; 108:718–727; doi: 10.1038/ajg.2013.63; published online 2 April 2013
1 Division of Gastroenterology, University of Michigan Health System , Ann Arbor , Michigan , USA ;
2 Monash University , Melbourne , Victoria , Australia .
Correspondence: William D. Chey, MD, AGAF, FACG, FACP , Division of Gastroenterology, University of Michigan Health System , 3912 Taubman Center,
SPC 5362, Ann Arbor , Michigan 48109-5362 , USA . E-mail:
Received 17 December 2012; accepted 11 February 2013
© 2013 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY
Fiber and Functional Gastrointestinal Disorders
e physiological characteristics (and potential health bene ts)
of each di erent  ber type, in turn, depends on its proportion of
soluble- and insoluble carbohydrate components. For example,
ber types that are high in soluble, viscous  ber may slow rates
of glucose and lipid absorption from the small intestine, likely by
sequestering bile acids and monoglycerides during passage through
the intestinal lumen ( 39 ). Soluble  ber (pectin, beta-glucan (from
oats and barley), ispaghula / psyllium) is believed to be bene cial
in lowering blood cholesterol and plaque-forming low-density
lipoprotein levels by interrupting the enterohepatic circulation of
bile salts, thereby increasing hepatic conversion of cholesterol into
newly synthesized bile acids and decreasing serum LDL ( 18 20 ).
Dietary  ber can contribute to net metabolizable energy, depend-
ing on how readily it is fermented. For example, fermentable  ber
contributes 8 kJ / g (resistant starch (8.8 kJ / g), fructo-oligosaccha-
rides (8.4 kJ / g ), and inulin (8.8 kJ / g)) and non-fermentable  ber
contributes (0 kJ / g) ( 40 ). Tabl e 2 lists popular commercially avail-
able supplements by type of  ber.
How fi ber affects GI function
Fiber has been advocated for improved bowel function since the
early 1970s ( 41 ). In a 1980 Nature article, Stephen and Cummings
( 42 ) demonstrated that the actions of soluble and insoluble  bers
in the colon depend on the extent to which they are digested. In
an elegant study they showed that insoluble  ber alters colonic
function by increasing fecal water content and fecal bulk.
e mechanism for this e ect was unclear, however, as insolu-
ble  ber has no appreciable water holding capacity, is minimally
fermented (no appreciable increase in biomass), and accelerates
colonic transit in germ-free rats ( 43,44 ). It was later determined
that insoluble  ber (e.g., wheat bran) increases fecal mass and
colonic transit rate through mechanical stimulation / irritation of
gut mucosa, inducing secretion and peristalsis ( 45 ). An additional
study showed that both particle size and shape were important,
with large, coarse particles providing greater laxative e cacy than
ne, smooth particles (no e ect) ( 46 ). Taken together, these data
support that insoluble  ber can have a signi cant laxative e ect,
but only if the particles are of su cient size and coarseness.
Soluble non-viscous  ber and soluble viscous  ber that is readily
fermented increase stool bulk by increasing biomass and fermen-
tation by-products, such as gas and SCFAs ( 42 ). On the basis of
such observations, it has been proposed that  ber improves FGIDs
through the acceleration of oro-anal transit and by decreasing
intra-colon pressure ( 47,48 ). Of course, it is also possible that it is
through secondary e ects on the microbiota, low-grade in amma-
tion, or permeability that ber exerts e ects on sensation as well
as transit ( Figure 1 ) ( 49 ). e consumption of  ber may actually
retard gas transit, by decreasing bolus propulsion to the rectum
( 50 ). us, in addition to increasing gas production by colonic
ora, ber ingestion may elicit gaseous or bloating symptoms by
promoting gas retention.
Soluble viscous  ber that is minimally fermented has a high
water-holding / gel-forming capacity that is preserved through-
out the large bowel, normalizing stool form (so ens hard stool in
constipation,  rms loose / liquid stool in diarrhea) ( 51,52 ). Viscous
bers that are FDA approved for laxation include methylcellulose,
calcium polycarbophil, and psyllium. Stool consistency is highly
correlated with stool water content, and a relatively small change in
stool water content (increase of 4.7 % ) can lead to a relatively large
stool so ening e ect (4.6-fold di erence in viscosity) ( 51 ).
Fiber also has extra-colonic e ects, and the data on gastric emp-
tying are mixed ( 53 57 ). In general, high doses ( 7 g) of wheat bran,
inulin, and psyllium tend to delay gastric emptying, whereas lower
doses do not show a signi cant e ect. Delayed gastric emptying
may be due to increased viscosity of gastric contents, which reduces
pyloric  ow. Increased viscosity reduces sedimentation of solids in
liquids and thus impairs the ability of the antrum to preferentially
empty liquids faster than solids ( 58,59 ).  is delay in gastric emp-
tying, together with a possible impairment of nutrient absorption
in the small intestine may delay intragastric redistribution, which
normally occurs as nutrients enter the duodenum ( 60 ).  is could
explain the tendency towards the higher antral / fundal ratios seen
with bran, leading to the sensation of distension and bloating ( 61 ).
Effects of SCFAs
Using in vitro fermentation models to produce estimates of in vivo
ber fermentation, there is evidence that soluble  bers increase the
rate of fermentation, increase SCFA production, lower pH, and
increase hydrogen gas production ( 62 ). In fact, di erences in fer-
mentation rates, gas production, and SCFA production have been
observed for various  ber preparations (wheat dextrin, psyllium,
inulin), which may in turn explain their clinically observed di erent
gastrointestinal tolerances. Of the SCFAs, butyrate is the preferred
energy source for the colonic mucosa cells and exerts e ects on
myenteric neurons and motility ( 63 ), supporting one mechanism by
which a high  ber diet accelerates colonic transit ( 64 ). Recent work
has found that speci c SCFAs such as butyrate alter the proportion
of ChAT immune reactive myenteric neurons and increase choliner-
gic-mediated colonic circular smooth muscle contraction in animals
( 63 ). Butyrate has also been shown to suppress colonic in ammation
by the inhibition of the IFN- γ / STAT1 signaling pathway ( 65 – 67 ).
SCFAs may also be shown to exert e ects on the GI tract
outside the colon. Exposure of the proximal colon in healthy
Short chain
fatty acids (SCFA)
(Butyrate, propionate,
of transit time
Effects on
and permeability
Likely mechanism of action of fiber
on intestinal transit time and visceral hypersensitivity
(CH4, H2, CO2)
Figure 1 . Likely mechanism of action of fi ber on intestinal transit time and
visceral hypersensitivity.
The American Journal of GASTROENTEROLOGY VOLUME 108 | MAY 2013
Eswaran et al
Table 1 . Naturally occurring fi ber types
Fiber type Chain length Sources Potential benefi ts for IBS
a Potential risks for IBS
Soluble highly fermentable
(includes FOS, GOS)
Legumes / pulses
Nuts and seeds
Wheat, rye
Onions, garlic,
Laxation: weak laxative effect.
Transit time: does not hasten transit time.
Balance of bacteria: selective growth of
certain microbiota, e.g., Bifi dobactia.
SCFA: very rapidly fermented in terminal
ileum and proximal colon to produce SCFA.
Gas production: high
In patients with IBS the rapid
fermentation may contribute to
gas, fl atus and gastrointestinal
A number of studies have been
undertaken in IBS with mixed
results ( 37 ).
Soluble highly fermentable
ber (e.g., RS, pectin,
guar gum, and inulin)
Legumes / pulses
Rye bread, barley
Firm bananas
groats (kashi),
millet, oats
Cooked and
potato and rice.
Laxation: Mild laxative effect.
Transit time: Does not hasten gut transit.
Can slow absorption from the small
Balance of bacteria: Increases overall
bacterial species but not selective for
bifi dobacteria.
SCFA: Rapidly fermented in proximal colon
to produce SCFA. RS is good an excellent
substrate for the production of the SCFA
Gas production: moderate
In patients with IBS the rapid
fermentation may contribute to
gas, fl atus, and gastrointestinal
No well-designed studies have been
undertaken in IBS.
Intermediate soluble
fermentable fi b e r
(psyllium / ispaghula)
and oats.
Seed of the plant
Plantago ovata ,
and oats
Laxation: good laxative effect.
Transit time: does hasten transit time.
Balance of bacteria: increases overall
bacterial species but little evidence for
selective growth
SCFA: moderately fermented along length
of colon to produce SCFA.
Gas production: moderate.
In patients with IBS studies have
shown some positive effect on
Side-effects of gas / atus has
produced mixed results for some
patients with IBS ( 38 ) .
Insoluble slowly fermentable
ber (e.g., wheat bran,
lignin (fl ax), fruit,
and vegetables)
Some vegetables
and fruit
Wheat bran
Wholegrain cereal
Brown rice,
pasta, quinoa
Flax seed.
Laxation: good laxative effect.
Transit time: does hasten transit time.
Balance of bacteria: increases overall
bacterial species but little evidence for
selective growth
SCFA: slowly fermented to produce SCFA
along the length of the colon.
Gas production: moderate-high
In patients with IBS wheat bran
has not been shown to be effective.
A major side-effect has been
excessive gas / wind and bloating
( 39 ). This may be due to the
presence of high quantities of
fructans also associated with the
wheat bran ( 40 ).
Symptoms associated with wheat
bran may not be acceptable to many
Insoluble, non-fermentable
(e.g. cellulose, sterculia,
and methylcellulose)
High fi ber grains
and cereals
Nuts, seeds
Skins of fruit and
Laxation: good laxative effect.
Transit time: does hasten transit time.
Balance of bacteria: no evidence
for selective growth.
SCFA: poorly fermented.
Gas production: low
Less gas / wind forming properties
This fi ber type may have better
characteristics for treating
constipation in IBS patients.
However, few well designed
studies have been conducted.
FOS, fructo-oligosaccarides; GOS, galacto-oligosaccarides; IBS, irritable bowel syndrome; RS, resistant starch; SCFA, short chain fatty acids.
Information given in this table is a simplifi ed overview that summarizes the different physiological effects of the different fi ber types. More detailed information about this
area may be obtained by key reviews cited in this paper ( 26 35,42 44,73,74,77 ).
a Using standard (not excessive) doses of these carbohydrates .
© 2013 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY
Fiber and Functional Gastrointestinal Disorders
volunteers to SCFAs results in marked dose-dependent relaxa-
tion of the proximal stomach, and triggers transient LES relaxa-
tions ( 68,69 ). Similar e ects have been observed in patients with
gastroesophageal re ux disease on a diet high in indigestible
carbohydrates (10 g  ber / day), signi cantly increasing the rate
of transient LES relaxations, number of acid re ux episodes,
and symptoms of gastroesophageal re ux disease ( 70 ).
Interaction with microbiota
ere is also evidence that changes in the complex gastrointes-
tinal environment by ingested  ber in uence fecal microbiota
pro les, perhaps because of the varied production of SCFAs
and / or decreases in colonic pH, promoting the growth of ben-
e cial bacteria ( Figure 1 ). Short-chain carbohydrates (inulin,
fructo-oligosaccharides / galacto-oligosaccharide) and other solu-
ble  bers are fermented in the distal small intestine and proximal
colon by endogenous bacteria to energy and metabolic substrates
(SCFAs), and the presence of these carbohydrates may produce
selective changes in the composition of the microbiota, inducing
di erent fermentation patterns. As such, carbohydrates such as
inulin are regarded as prebiotics, which may stimulate or alter the
preferential growth of health-promoting species already residing
in the colon (especially, but not exclusively, lactobacilli and bi do-
bacteria) ( 71 – 75 ), leading to potential bene ts in irritable bowel
syndrome (IBS) ( 76 ).
Fiber for chronic constipation
In addition to adequate  uid intake and exercise, a high  ber diet
is o en the  rst recommendation a patient will receive for chronic
constipation, as a lack of dietary  ber is believed to contribute to
constipation ( 77 – 79 ). Although 50 % of patients think ber does
not completely relieve their constipation and almost two-thirds of
respondents are not completely satis ed with the ability of  ber to
improve their quality of life ( 80 ), current guidelines recommend
the use of  ber in both dietary and supplement form for the early
management of constipation ( 81 ) ( Table 3 ( 82 )). It is apparent
from trials identi ed by systematic reviews that there is a relative
paucity of high quality evidence to support this approach, espe-
cially for insoluble  ber. Soluble  ber is thought to increase stool
bulk and weight and therefore stool frequency ( 3,83 ). Insoluble
ber such as bran is thought to accelerate intestinal transit time,
thereby increasing stool frequency ( 43,45,84 ). Finally, there is a
particular lack of evidence of e cacy of ber for individual con-
stipation subtypes (obstructive, metabolic, neurological, diet-
related, myogenic, drug-related, and pelvic  oor dysfunction).
us, the remainder of this discussion will focus on  ber as a
treatment for chronic idiopathic constipation (CIC), or constipa-
tion unrelated to anatomic, medication-related, or readily identi-
able physiological causes.
Fiber supplements. In an attempt to make sense of the divergent
data addressing the role of  ber as a treatment for constipation, a
number of systematic reviews and meta-analyses with varying se-
lection criteria have been published ( 2,85,86 ).  ese analyses have
found that most studies su er from small sample sizes and poor
study design with non-rigorous outcomes and high risk of bias.
Acknowledging the inherent heterogeneity of the data, there does
appear to be a signi cant improvement in constipation symptoms
Table 2 . Commercially available fi ber preparations
Fiber category Type Brand Serving size Amount of fi ber per serving
Soluble highly fermentable
FOS Orafti-P95 Powder 8 g / day 7.5 g
Soluble highly fermentable fi ber Inulin FiberChoice
Benefi ber (Canada)
Metamucil clear
2 Tablets
1 teaspoon
4 5 g
Wheat dextrin Benefi ber (USA) 2 Teaspoon powder 3 g
Partially hydrogenated guar
gum (PHGG)
Resistant starch
Benefi ber (formerly)
15 20 g powder
7 9 g
Soluble intermediate fermentable
Ispaghula / psyllium
Oat Bran
Quaker oats
1 Tsp
Powder, caplet, wafer
g dry
3 g
4 g (2 g soluble)
Insoluble, minimally fermentable
Wheat Bran Available in supermarket 15 g Coarse powder
19 g Bran-pellets
6.5 g
4.5 g
Insoluble, non-fermentable fi ber Methylcellulose
a Citrucel Varies 0.5 2 g
Karaya gum / sterculia
b Normacol
Normafi b
1 2 Sachets daily or bid 7 g Per sachet
FOS, fructo-oligosaccarides.
a Derivatives of insoluble fi bers (e.g., esters of cellulose) are generally used. These derivatives are soluble in cold water.
b Sterculia gum is available as granules which should be swallowed whole with plenty of water.
The American Journal of GASTROENTEROLOGY VOLUME 108 | MAY 2013
Eswaran et al
Di culty of defecation was also signi cantly reduced with rye
bread ( P < 0.001), and stools were so er ( P < 0.001). However,
there were higher symptoms scores for gastrointestinal side e ects
such as abdominal pain,  atulence, borborygmi, and bloating
with rye bread compared with low  ber bread (mean di erence in
scores = 1.6, P < 0.001). Note that rye is partially fermentable, and
the high dose (37 g / day) was started day 1 without a gradual intro-
duction of  ber.
Little human data exist on other commercially available  ber
preparations ( Ta ble 3 ). For example, one study of methylcellulose
in constipated patients resulted in statistically signi cant increases
in stool frequency, water content, and fecal solids but this was
neither randomized or placebo controlled ( 95 ).
Fiber e ects on constipation subtype. Non-response to supple-
mentary  ber may be a marker of refractory constipation or con-
stipation subtype, though there are few studies that have assessed
the e cacy of ber for slow transit constipation or dyssynergic
defecation. One non-randomized study demonstrated 88 % of
patients with slow transit and 63 % of patients with a disorder of
defecation did not respond to dietary  ber treatment (30 g of  ber
per day), whereas 85 % of patients without a pathological  nding
improved or became symptom free ( 96 ). Approximately half of
patients with symptoms refractory to supplementary  ber have a
prolonged intestinal transit time ( 97 ).  us, ber intake is not a
panacea for all CIC patients.
Dietary  ber. Patients o en  nd  ber supplements inconvenient
and unpalatable with the occurrence of gas or bloating o en a
reason for lack of compliance or discontinuation of therapy ( 98 ).
Comparatively, few clinical trials have evaluated dietary  ber that
is naturally occurring as opposed to supplemental  ber, likely
because food contains not only  ber but other non-absorbable
sugars (i.e., polyols, fructans, and galacto-oligosaccharides) or
chemicals, which may exert laxative e ects. For example, a recent
prospective, randomized-controlled 8-week single-blind cross-
over study examined treatment with dried plums (prunes, 6 g / day
ber) compared with psyllium (6 g / day ber) in 40 patients ( 99 ).
Dried plums not only contain  ber but also sorbitol and fructans,
non-absorbable carbohydrates that, when fermented by colonic
bacteria, create an osmotic load that can dramatically alter stool
frequency and consistency ( 100 ). Treatment with dried plums
resulted in a greater improvement in constipation symptoms
as re ected by a signi cant increase in the number of complete
spontaneous bowel movements and in stool consistency (so er
stools) when compared to treatment with psyllium. Also, more
subjects reported subjective improvement in overall constipa-
tion symptoms, although the mean global constipation symptom
scores were similar between groups and psyllium also improved
constipation symptoms when compared with baseline.
Conclusion. As there may be some bene t and little risk of seri-
ous adverse events, increasing dietary  ber or the addition of  ber
supplements seems a reasonable initial strategy in the manage-
ment of CIC patients. Patients may enjoy improvements in bowel
and abdominal discomfort compared with placebo for soluble
ber (psyllium, inulin).  e paucity of high quality data highlights
the need for further large, methodologically rigorous, randomized
controlled trials (RCTs) utilizing validated outcome measures as
de ned by the Rome Foundation and regulatory agencies such
as the US Food and Drug Administration and the European
Medicines Agency ( 87 ).
e most recent summary of available RCTs studying the
e ects of both soluble and insoluble  ber in patients with CIC
was performed in 2011 by Suares et al ( 88 ). Six studies were found
eligible for inclusion, including one RCT, which utilized a cross-
over design. It should be noted that studies which recruited patients
with drug-induced constipation, institutionalized patients, or those
that enrolled a heterogeneous group of patients (e.g., both CIC
and IBS with constipation (IBS-C)) were excluded. None of these
was at low risk of bias, the majority of them were small, and none
accounted for baseline dietary  ber consumption or change in  ber
consumption during the study. Amounts of  ber in these studies
ranged between 10 – 20 g of ber / day with a treatment duration
from 2 to 8 weeks.  e settings were mostly tertiary care centers and
subjects were predominantly female. Four of the eligible trials used
soluble  ber (3 with psyllium, 1 with inulin and malto-dextrin)
( 89 – 92 ). e largest trial was a single-blind RCT with 201 primary
care patients who underwent treatment over a 2-week period ( 89 ).
Eighty-seven percent of patients allocated to psyllium reported an
improvement in symptoms, compared with 47 % of patients receiv-
ing placebo ( P < 0.001). ere was also a signi cant response in
abdominal pain / discomfort and straining on defecation. Similar
e ects were seen among the other three trials of soluble  ber. In
one study, pain with defecation was signi cantly reduced with psyl-
lium, but 18 % of psyllium patients reported abdominal pain as a
side e ect as compared with 0 % of placebo ( 90 ).
Two studies used insoluble  ber, wheat bran in one study ( 93 )
and rye bread in the other ( 94 ). In the 24 patients recruited to
receive 20 g of bran per day or placebo, no statistically signi cant
di erence in response (de ned as having no further straining at
stool) occurred with active treatment. For the rye bread study,
29 female participants consumed rye bread (37 g / day  ber) or
low  ber bread (6.6 g / day ber) over a 3-week period. Following
the intervention period, the mean di erence in number of stools
per day was 0.3 higher for the patients randomized to rye bread
compared with those assigned to low- ber bread ( P = 0.001).
Table 3 . Commonly used therapeutics for constipation and level
and grade of evidence ( 82 )
Treatment modalities commonly
used for constipation
Recommendation level and grade
of evidence
Bulking agents
Psyllium / ispaghula Level II; grade B
Calcium polycarbophil Level III; grade C
Bran Level III; grade C
Methycellulose Level III; grade C
© 2013 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY
Fiber and Functional Gastrointestinal Disorders
movement frequency and consistency. E ects on other symptoms
commonly reported by CIC patients such as abdominal pain or
bloating are more variable. Non-evidence based but practical ad-
vice on initiating therapy with  ber supplements includes starting
at a nominal dose and slowly titrating up as tolerated over the
course of weeks to a target dose of 20 30 g of total dietary and
supplementary  ber per day ( Table 2 ). It is also reasonable to rec-
ommend clearing hard stool with an osmotic laxative before initi-
ating  ber therapy, which may avoid cramping pain. Occasionally,
patients will experience marked worsening of their constipation
related symptoms with  ber. When this occurs, there are some
data to suggest that signi cantly delayed colon transit or dyssyn-
ergic defecation might be present ( 96,97 ).
Fiber for IBS. Historically, increasing dietary ber intake has
been a standard recommendation for patients with IBS, but the
e cacy of ber for IBS is more nuanced than appreciated by
most clinicians. Ever since Burkitt et al. ( 41 ) rst suggested that
ber might protect people in rural areas from certain gastroin-
testinal disorders, the practice of advising  ber supplementation
in FGIDs has become widespread and remains standard operat-
ing procedure. However, the use of  ber for IBS has historically
been, and still remains, controversial. Although some believe that
the highly processed, low  ber western diet is at the root of IBS,
others believe that roughage can exacerbate or even cause IBS
symptoms ( 41,101 ). ese divergent views are likely the result of
the inherent heterogeneity of IBS, confusion as to what we refer
to as  ber, the paucity of high quality studies, and con icting his-
torical data. In 1977, Manning et al. ( 102 ) examined the e ect of a
6-week high- or low- ber diet on abdominal pain and bowel fre-
quency in 26 IBS patients. Participants in this single-blind RCT
ingested an additional 20 g of wheat bran per day on the high
ber diet.  e investigators found signi cant improvement in
pain frequency ( P < 0.05) and pain severity ( P ~ 0.01). Bowel habit
was regarded as “ improved ” in the high ber group ( P < 0.05),
and bowel frequency improved modestly as well ( P < 0.02). An-
other seminal RCT of psyllium in 80 IBS patients signi cantly
improved constipation ( P = 0.026) and transit time ( P = 0.001)
but did not signi cantly improve bloating and abdominal pain
( 103 ). A subsequent non-randomized study investigated the util-
ity of high- ber diets (30 g of  ber / day) for the treatment of
72 IBS patients (all subtypes).  is study reported improvement
in hard stools, bowel frequency, and urgency but no change in
abdominal distension, diarrhea, or  atulence ( 104 ). Finally, an
o en-cited patient survey of 100 IBS patients found that 55 % felt
worse and only 10 % felt better on bran ( 105 ).
Fiber intake in IBS. A recent survey found that most general
practitioners believe that  ber de ciency is the main cause of IBS
symptoms and 94 % would institute dietary therapy based on this
assumption ( 106 ). However, patients with FGIDs do not seem to
consume less dietary  ber than healthy controls, suggesting symp-
toms are unlikely to be related to altered diet composition ( 107 ).
A recent Swedish abstract that compared the nutrition intake in
patients with IBS with the general population actually found the
intake of dietary  ber to be higher in the IBS group (19 vs. 16 g /
day, P < 0.001) compared with controls ( 108 ). e authors con-
cluded that although IBS patients may have a self-imposed limited
diet and avoid trigger foods, their mean average daily  ber intake
is essentially similar to that of a matched healthy control popula-
tion and in accordance with current nutrition recommendations.
Fiber supplements in IBS. e use of  ber or bulking agents
for treatment of IBS has been summarized in two meta-analy-
ses ( 109,110 ), four systematic reviews ( 37,111 113 ), and two
comprehensive narrative reviews ( 114,115 ). All noted signi -
cant quality shortcomings in the published studies, including
heterogeneous patient populations, varied outcome measures,
di erent types of  ber supplements, small sample size, and dif-
culties with blinding. Other widely variable factors included
the amount of soluble (5 – 30 g) and insoluble (4.1 – 36 g) ber
added to the diet and the duration of study intervention (3 16
weeks). Most of the trials that report the use of these agents do
not adhere to the recommendations made by the Rome foun-
dation for the design of treatment trials for the functional GI
disorders ( 87 ), although this is largely because the majority of
these trials were conducted long before these guidelines were in
place. Finally, most studies evaluated supplementary  ber and
not increased dietary  ber, and rarely reported on IBS subtype
or baseline dietary  ber consumption.
e most recent Cochrane analysis concluded that bulking
agents were not bene cial for the treatment of IBS ( 112 ).  is anal-
ysis, which included 12 papers with an intervention period lasting
4 16 weeks, reiterated the problems with the quality of available
data.  e authors conclusions from the pooled data suggested
that bulking agents provided no bene t for the treatment of IBS.
e studies either showed no signi cance or did not address spe-
ci c outcomes, including abdominal pain, improvement in global
assessment, and IBS symptom scores. Only seven of the included
studies had more than 30 patients and all studies had quality
limitations (i.e., method of randomization, double-blinding, con-
cealment of treatment allocation, description of withdrawals).
In a systematic review and meta-analysis by Ford et al. , ( 109 )
12 trials and 591 patients were included that evaluated the e -
cacy of various forms of  ber with placebo or, in one study, a low
ber diet as treatment for IBS. Only 3 of these 12 studies reported
on IBS subtype. Two of the studies included only IBS-C patients
and another had 49 % IBS-C patients.  e ber preparations used
included bran ( ve studies), ispaghula / psyllium (six studies), and
one unspeci ed. Overall, 52 % of IBS patients assigned to  ber
had persistent symptoms or no improvement in symptoms a er
treatment compared with 57 % assigned to placebo or a low  ber
diet (relative risk (RR) 0.87, 95 % con dence interval (CI) = 0.76 –
1.00, P = 0.05). ere was no statistically signi cant heterogeneity
detected between studies ( I 2 = 14.2 % , P = 0.31). e number needed
to treat (NNT) with  ber to prevent one patient with persistent
symptoms was 11 (95 % CI = 5 – 100). ere was no evidence of
funnel plot asymmetry, suggesting no publication bias. However,
only seven of the 12 studies scored 4 or more on the Jadad scale.
When only these seven higher quality studies were included in the
The American Journal of GASTROENTEROLOGY VOLUME 108 | MAY 2013
Eswaran et al
patients reporting no change. In primary-care, psyllium led to
improvement in 25 % , deterioration in 19 % and no change in
56 % , which was not signi cantly di erent to secondary-care.  e
authors concluded that although the approach of advising bran
for patients with IBS is not especially bene cial, it may be better
tolerated in primary care settings.
Although few adequately powered, methodologically rigorous
studies have examined the role of commercially available  bers other
than psyllium for the treatment of IBS symptoms, there are some data
to suggest that preparations such as partially hydrolyzed guar gum
(formerly Bene ber, Novartis Consumer Health Inc., Parsippany, NJ)
and calcium polycarbophil (Fibercon, P zer, New York, NY) may
be helpful and well tolerated ( 118 120 ). It should be noted that each
caplet of calcium polycarbophil contains roughly 0.5 g of  ber, thus
multiple pills may be required to see an appreciable e ect.
Dietary  ber. In contrast to the larger number of studies of  ber
supplementation, few studies have examined the e ect of increas-
ing  ber intake in the form of ordinary foods ( 121 123 ).  ere
are reports of improvement of IBS symptoms on both high- ber
and low- ber diets, a result attributed to a placebo or Hawthorne
e ect. In fact, a number of contrarian studies had suggested that
popular sources of dietary  ber, such as bran, cereals, vegetables,
and fruits, might actually aggravate symptoms in IBS as these
foods also contain large amounts of FODMAPs (e.g., fructans, ex-
cess fructose, galacto-oligosaccharide, and sugar polyols) ( 124 ).
e symptoms that appeared to be aggravated most commonly
were  atulence, bloating, and abdominal pain.
Success in  nding an e ective treatment strategy for treating
functional GI disorders is a challenging area of clinical manage-
ment. One of the aims of this review was to highlight the impor-
tance of assessing the fermentation characteristics of each  ber
type when choosing a suitable strategy for patients. When  ber
is recommended for FGIDs, use of a soluble supplement such as
ispaghula / psyllium is best supported by the available evidence. In
constipated patients, it can be helpful for pre-existing hard stool
to be eliminated (e.g., with an osmotic laxative) before initiat-
ing  ber therapy. Fiber should be started at a nominal dose and
slowly titrated up as tolerated over the course of weeks to a tar-
get dose of 20 30 g of total dietary and supplementary  ber per
day. Even when used judiciously,  ber can exacerbate problems
with abdominal distension,  atulence, constipation, and diarrhea
( 105,125,126 ). It is clear that rather than extrapolating from the
studies undertaken in healthy individuals, further research in
functional GI patients should be performed with rigorous end-
points, strict inclusion criteria, and IBS subtype in mind.
e authors would speci cally like to thank Dr John McRorie for
his contributions and edits to the Fiber metabolism section of the
analysis, the borderline treatment bene t for  ber was no longer
evident (RR of persistent symptoms (0.90, 95 % CI = 0.75 – 1.08).
e data would suggest that all types of  ber supplementation
are not created equally, at least not as it pertains to the treatment of
IBS. In  ve studies (221 patients), which compared insoluble bran
with placebo or a low  ber diet, bran failed to improve overall IBS
symptoms (RR of persistent or unimproved symptoms 1.02, 95 %
CI = 0.82 – 1.27) ( 109 ). On the other hand, six studies (321 patients)
evaluated soluble  ber (ispaghula / psyllium) vs. placebo. Ispaghula
was e ective at improving overall IBS symptoms (RR of persistent
or unimproved symptoms 0.78, 95 % CI = 0.63 – 0.96). e NNT for
ispaghula to prevent one patient from experiencing persistent symp-
toms was 6 (95 % CI = 3 – 50). ere was no evidence of funnel plot
asymmetry and 5 / 6 studies scored 4 or more on the Jadad scale.
One key di erence between the Ford and Cochrane reviews was
the method of analysis ( 109,112 ). Both analyses had similar strict
inclusion criteria, but Ford et al. ( 109 ) did not use an intention-
to-treat analyses, and used persistent symptoms a er treatment as
an outcome measure.  is may explain why this group found
psyllium to have a small but statistically signi cant bene t for IBS.
e most recent comparative e ectiveness trial evaluated the rela-
tive e cacy of psyllium / ispaghula, 10 g ( n = 85), bran, 10 g ( n = 97),
or rice  our (placebo) ( n = 93), twice daily (mixed with food, pref-
erably yogurt) over 12 weeks in 164 primary care IBS patients
( 116 ). is study was not included in the reviews mentioned above.
At 1 month, 57 % of patients taking psyllium experienced adequate
symptom relief for 2 / 4 weeks of treatment compared with 40 % with
bran (NNT = 6, 95 % CI = 4 – 104) and 35 % with placebo (NNT = 5,
95 % CI = 3 – 15). e di erence between psyllium and placebo, how-
ever, was no longer signi cant at 3 months. Bran provided bene ts
over placebo only at 3 months. Over 60 % of subjects randomized to
psyllium or bran reported moderate adverse events, the most com-
mon of which were constipation and diarrhea. Interpretation of the
results at 2 and 3 months of treatment are complicated by the high
drop-out rates (29 % and 40 % , respectively). e overall likelihood
of side e ects was similar among the three groups.
It is important to recognize that most of the data on the e cacy
of  ber for IBS come from referral centers. Studies conducted in
referral centers are likely to be biased against  ber supplemen-
tation, as patients who improve with  ber are less likely to be
referred to a tertiary care center.  us, it is possible that results
of trials evaluating from referral centers could underestimate the
bene ts of  ber for IBS. Only a few studies have included primary
care patients exclusively ( 105,116 ), and only one has addressed
this potential di erence in response speci cally. Miller et al.
( 117 ) recruited consecutive patients meeting Rome I criteria for
IBS from primary and secondary clinics until 100 had completed
questionnaires. Twenty-seven percent of primary care patients
said that bran had improved their symptoms compared with 22 %
who claimed it had made them worse. Ten percent of secondary
care patients attributed improvement to bran, while 55 % of these
patients felt it exacerbed their symptoms. About half of primary
care patients (51 % ), reported that bran had no positive or nega-
tive e ect on their symptoms compared with 33 % of secondary
© 2013 by the American College of Gastroenterology The American Journal of GASTROENTEROLOGY
Fiber and Functional Gastrointestinal Disorders
Guarantor of the article : William D. Chey, MD, AGAF, FACG, FACP.
Speci c author contributions: Dr Eswaran dra ed the
manuscript and prepared the tables. Dr Muir contributed to the
writing, referencing, and preparation of the manuscript and tables.
Dr Chey proofed and  nalized the text. All authors approved the
nal dra submitted.
Financial support : None.
Potential competing interests: Dr Eswaran and Jane Muir have no
potential competing interests. William D. Chey is a consultant for
N e s t l é / P r o m e t h e u s .
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... Notably, ginger comprises biologically active constituents, notably the pungent gingerols and shogaols (Prakash et al., 2012) [25] . In the context of bread production, wherein diverse functional ingredients are introduced to enhance nutritional value and fulfill specific functional roles, the inclusion of such ingredients has surged in popularity due to their potential to mitigate chronic disease risks beyond basic nutritional functions (Eswaran et al., 2013) [15] . ...
... Notably, ginger comprises biologically active constituents, notably the pungent gingerols and shogaols (Prakash et al., 2012) [25] . In the context of bread production, wherein diverse functional ingredients are introduced to enhance nutritional value and fulfill specific functional roles, the inclusion of such ingredients has surged in popularity due to their potential to mitigate chronic disease risks beyond basic nutritional functions (Eswaran et al., 2013) [15] . ...
The present investigation involved the development of ginger-flavored bread utilizing a composite flour consisting of wheat and soy. Different amounts of ginger powder (0%, 3%, 5%, and 7%) were employed in the formulation. The evaluation included the determination of antioxidant activity, proximate composition, and sensory attributes through the use of hedonic testing. The bread with 7% ginger demonstrated the greatest degree of antioxidant activity (24.42±4.03). However, it was observed that the sensory quality of the bread was reduced, particularly when larger doses of ginger were used. The gingerbread containing 3% ginger exhibited notable sensory characteristics and had noteworthy antioxidant properties when compared to the control group. However, it is important to note that these differences were not found to be statistically significant (p>0.05) in the majority of sensory aspects. The gingerbread with a ginger concentration of 3% exhibited a higher protein content as a result of the use of soy flour. However, as the ginger concentration increased, the protein content decreased. Furthermore, the inclusion of ginger concentration resulted in a rise in moisture content, crude fiber, and ash content, with the exception of ash, crude fiber, and moisture content, which exhibited a decrease at the maximum level of ginger utilized.
... 110 Dietary fiber, especially insoluble fiber, may also aggravate constipation-related symptoms (such as abdominal distention and flatulence). 111 ...
... 124 Therefore, these concerns should be considered during treatment; they can be addressed by prescribing osmotic laxatives before increasing the dietary fiber intake or by slowly increasing the fiber intake from an initial small dose (depending on the tolerance and efficacy). 111 Magnesium salts are considered excellent conventional laxatives; they are osmotic laxatives that mainly soften hard stools. They have low costs, allow easy dosage adjustment, and are easily ingested. ...
Chronic constipation is one of the most common digestive diseases encountered in clinical practice. Constipation manifests as a variety of symptoms, such as infrequent bowel movements, hard stools, feeling of incomplete evacuation, straining at defecation, a sense of anorectal blockage during defecation, and use of digital maneuvers to assist defecation. During the diagnosis of chronic constipation, the Bristol Stool Form Scale, colonoscopy, and a digital rectal examination are useful for objective symptom evaluation and differential diagnosis of secondary constipation. Physiological tests for functional constipation have complementary roles and are recommended for patients who have failed to respond to treatment with available laxatives and those who are strongly suspected of having a defecatory disorder. As new evidence on the diagnosis and management of functional constipation emerged, the need to revise the previous guideline was suggested. Therefore, these evidence-based guidelines have proposed recommendations developed using a systematic review and meta-analysis of the treatment options available for functional constipation. The benefits and cautions of new pharmacological agents (such as lubiprostone and linaclotide) and conventional laxatives have been described through a meta-analysis. The guidelines consist of 34 recommendations, including 3 concerning the definition and epidemiology of functional constipation, 9 regarding diagnoses, and 22 regarding managements. Clinicians (including primary physicians, general health professionals, medical students, residents, and other healthcare professionals) and patients can refer to these guidelines to make informed decisions regarding the management of functional constipation.
... Individual tolerance to fiber and prebiotics varies. Modest reductions in the consumption of fiber-rich foods may be due, in part, to discomforts such as bloating, cramps, and increased flatulence that are experienced post-fiber consumption [41]. This is a crucial consideration when devising nutritional plans for athletes, particularly when aiming to boost fiber intake, and especially during competitions. ...
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The search to comprehend the fundamental physiological factors that contribute to the exceptional endurance performance of elite human athletes is a long-standing endeavor within the field of sports science research [...]
... According to the study by Eswaran et al. (2013), dietary fibers of various types can be differentiated by their fermenting properties in the colonic lumen. The ones with greater fermenting properties include inulin, oligofructose, and psyllium, which are considered soluble dietary fibers relative to those with lesser fermenting abilities, including cellulose and hemicellulose, which are insoluble forms of dietary fiber. ...
The present study was conducted to assess selected galacto-oligosaccharides (GOS) effects on short-chain acids (SCFA), microbiota variability in in vitro, and health benefits using an animal model. In the in-vitro anaerobic batch, fermentation was applied to different groups divided by a varied amount of GOS sources, mixtures, and prebiotics. Results reported that SCFA for inulin contributed significantly higher for acetic, propionic, and butyric acids, and resistant starch (RS) showed a non-significant effect for acetic and propionic acids whereas the combined effect of GOS and RS showed higher values for parameters. For bacterial enumeration of bifidobacteria compared to individual GOS, synergistic effects were documented. The Sprague-Dawley rats given GOS under western diet influence relative to a high-fat diet alone observed after 1 and 4 weeks documented significant levels for acetic and butyric acid production, whereas body and organ weights for cecum tend to increase after 4 weeks of dietary intervention (p<0.05). Microbiome data using gene sequencing revealed a higher proportion of firmicutes and lower Bacteroides in control rats, which means Lachnospiraceae family abundances were higher in HF+GOS group. Overall, GOS fermentation showed an increment in the bifidobacterial population and tend to raise levels of SCFA in rats fed on a high-fat diet alone, whereas non-significant variation was reported in microbiome diversity after intervention. The present study was conducted to assess selected galacto-oligosaccharides (GOS) effects on short-chain acids (SCFA), microbiota variability in in vitro, and health benefits using an animal model. In the in-vitro anaerobic batch, fermentation was applied to different groups divided by a varied amount of GOS sources, mixtures, and prebiotics. Results reported that SCFA for inulin contributed significantly higher for acetic, propionic, and butyric acids, and resistant starch (RS) showed a non-significant effect for acetic and propionic acids whereas the combined effect of GOS and RS showed higher values for parameters. For bacterial enumeration of bifidobacteria compared to individual GOS, synergistic effects were documented. The Sprague-Dawley rats given GOS under western diet influence relative to a high-fat diet alone observed after 1 and 4 weeks documented significant levels for acetic and butyric acid production, whereas body and organ weights for cecum tend to increase after 4 weeks of dietary intervention (p<0.05). Microbiome data using gene sequencing revealed a higher proportion of firmicutes and lower Bacteroides in control rats, which means Lachnospiraceae family abundances were higher in HF+GOS group. Overall, GOS fermentation showed an increment in the bifidobacterial population and tend to raise levels of SCFA in rats fed on a high-fat diet alone, whereas non-significant variation was reported in microbiome diversity after intervention.
... Bakery goods range in complexity from bread and cakes to biscuits (crackers and cookies) and all three rely on wheat flour as a primary component due to its ability to add both volume and structure (Lai and Lin, 2007).Daily consumption of bakery goods is significant, and they play a crucial part in human nutrition. Functional ingredients in baked goods are gaining popularity not just for their nutritional value, but also for their potential to lower the risk of chronic disease (Eswaran et al., 2013). Wastes obtained from food industry are abundant sources of useful components like fiber, minerals, and phytochemicals. ...
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Agriculture has a significant role in ensuring food security and expanding access to food. Although it is predicted that global food demand will increase in the next years, whether or not agriculture can increase food production to fulfil this demand is uncertain. Pakistan is nearly food self-sufficient, despite only using 30% of its potential 6579 agricultural output. Even so, the country's population continues to consume significantly less food than is advised by the national food security line. Thirty percent of the food gap in the country is made up of food that is available but is not being eaten due of various barriers caused by the economic, physical, and sometimes natural situations.The largest amount of loss is attributable to fruits and vegetables, which account for 0.5 billion tones. Losses of fruits and vegetables are substantial in developing countries at the agricultural stage, but they are primarily characterized by the processing stage, which accounts for 25% of total losses. Food losses are high specially in developing countries. To alleviate this challenging issue different wastes from agricultural products like fruit and vegetable peels are incorporated into different food lines like bakery products, beverages, probiotics and confectionary products etc., where such peels used as a substitute of different food products and additionally provide nutritive final food product which along with helping the food security issue, help in providing rich food products.
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In recent years there has been growing interest in the use of nutraceuticals and biotics in both pediatric and adult clinical practice. The overlapping and often ambiguous symptoms of both functional and organic gastrointestinal disorders have led to a search for alternative therapeutic approaches that avoid the use of synthetic or chemical treatments. However, while nutraceuticals and natural supplements are widely used, their health benefits are often not supported by adequate scientific evidence, and an unregulated use of nutraceuticals can be potentially harmful. The correct use of nutraceuticals, prebiotics, and probiotics can optimize the results of drug therapy in some cases and reduce the risk of side effects. This review aims to provide clinicians with guidance on the use of complementary therapies for pediatric gastrointestinal symptoms and disorders, highlighting the scarcity of studies on the kinetics and dynamics of nutraceuticals and biotics. While it is generally difficult to associate their intakes with adverse events due to the often-coexisting pharmacological treatments, it is essential to avoid the abandonment of traditional drugs with proven efficacy in the treatment of single diseases. Overall, the use of nutraceuticals, prebiotics, and probiotics in pediatric gastroenterological practice requires caution and medical supervision. Further research is needed to determine the effects of alternative therapies on pediatric gastrointestinal symptoms and disorders, and to ensure their safe and effective use in the clinical practice.
Background and Objectives Dietary fiber (DF) plays a crucial role in promoting human health and preventing diseases. However, the average intake of fiber falls short of the recommended levels in affluent populations, largely due to the overconsumption of high‐energetic foods. Fortification of widely consumed foods with fiber can help address such population deficiencies. Findings Although fiber fortification can affect product quality, it offers practical advantages such as gelling, thickening, and water‐binding properties. This review focuses on the impact of isolated fiber ingredients, including arabinoxylan, β‐glucan, cellulose, resistant starch, and pectin, on bakery products, and fiber quantification methods to ensure accuracy and comparability in research. The structural interactions of DF during processing, sensory evaluation, and health implications are discussed. Alternative/novel fiber sources are explored as a strategic approach to enhance product attributes. Conclusions Considerable research has focused on individual fibers, but little is known about the synergistic effects of combining multiple fiber ingredients. Significance and Novelty Combining different fibers in food products could optimize their nutritional profile and enhance ingredients' performance in the food matrix.
Inflammatory bowel disease (IBD) encompasses a collection of idiopathic diseases characterized by chronic inflammation in the gastrointestinal (GI) tract. Patients diagnosed with IBD often experience necessitate long-term pharmacological interventions. Among the multitude of administration routes available for treating IBD, oral administration has gained significant popularity owing to its convenience and widespread utilization. In recent years, there has been extensive evaluation of the efficacy of orally administered herbal medicinal products and their extracts as a means of treating IBD. Consequently, substantial evidence has emerged, supporting their effectiveness in IBD treatment. This review aimed to provide a comprehensive summary of recent studies evaluating the effects of herbal medicinal products in the treatment of IBD. We delved into the regulatory role of these products in modulating immunity and maintaining the integrity of the intestinal epithelial barrier. Additionally, we examined their impact on antioxidant activity, anti-inflammatory properties, and the modulation of intestinal flora. By exploring these aspects, we aimed to emphasize the significant advantages associated with the use of oral herbal medicinal products in the treatment of IBD. Of particular note, this review introduced the concept of herbal plant-derived exosome-like nanoparticles (PDENs) as the active ingredient in herbal medicinal products for the treatment of IBD. The inclusion of PDENs offers distinct advantages, including enhanced tissue penetration and improved physical and chemical stability. These unique attributes not only demonstrate the potential of PDENs but also pave the way for the modernization of herbal medicinal products in IBD treatment.
Background and study aims: Childhood functional constipation (FC) is gradually becoming an emerging public health problem. This study aimed to develop a personalized nomogram for the prediction of incident FC among Chinese children, and the diagnosis of FC was based on the Rome IV criteria. Patients and methods: This cross-sectional study was conducted from Nov. 2020 to Jan. 2021 among children residing in Anhui province, China. An electronic questionnaire regarding the general demographic and clinical characteristics of all children was completed by their primary caregivers. The multivariate logistic regression analysis was applied to identify risk factors for FC. Moreover, a nomogram was constructed for FC based on the risk factors identified from the multivariate analysis. Results: In this study, a total of 901 electronic questionnaires were collected, of which 832 (92.3%) questionnaires were properly completed and included in the final analysis. The prevalence of FC among Chinese children was 11.3% based on the Rome IV criteria. After controlling for potential confounding factors, the multivariate logistic regression analysis showed that inadequate sleep, picky eating, and positive family history of FC were identified as key risk factors of FC. The area under the receiver operating characteristic curve of the nomogram was 0.694 (95 %CI: 0.6412-0.7459). Further, a calibration curve drawn illustrated that the predicted probabilities reasonably approximately the actual prevalence of FC in this population. Conclusion: Inadequate sleep, picky eating, and positive family history of FC were identified as risk factors of FC. An easy-to-use nomogram was constructed based on these three significant factors. Besides, this nomogram was validated to have acceptable discrimination and calibration capabilities. Hence, this nomogram may enable clinical professionals to predict the risk of FC among Chinese children and further provide optimized disease prevention and intervention for this population.
Introduction: The consumption of resistant dextrin improves constipation, while its fermentation and degradation by the intestinal microbiota produce short-chain fatty acids (SCFA) and lactic acid, which have beneficial effects on host metabolism and immunity. Mg oxide (MgO) is an important mineral that is used to treat constipation. Therefore, resistant dextrin and MgO are often administered together to improve constipation. However, limited information is available regarding the effect of this combination on SCFA and lactic acid production. Method: Crl:CD1(ICR) mice were fed a Mg-free diet with 5% resistant dextrin, followed by oral administration of MgO. We collected the cecum contents and measured SCFA and lactic acid levels. Additionally, the human subjects received resistant dextrin and Mg supplements as part of their habitual diet. Results: The results of this study demonstrate that intestinal microbiota cannot promote SCFA and lactic acid production in the absence of Mg. In a mouse model, low doses of MgO promoted the production of SCFA and lactic acid, whereas high doses decreased their production. In humans, the combined consumption of resistant dextrin and Mg supplements increased the production of SCFA and lactic acid. Conclusion: The production of SCFA and lactic acid from dietary fiber may be augmented by the presence of MgO.
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We aimed to assess the effects of psyllium supplementation on insulin sensitivity and other parameters of the metabolic syndrome in an at risk adolescent population. This study encompassed a participant-blinded, randomized, placebo-controlled, crossover trial. Subjects were 47 healthy adolescent males aged 15-16 years, recruited from secondary schools in lower socio-economic areas with high rates of obesity. Participants received 6 g/day of psyllium or placebo for 6 weeks, with a two-week washout before crossing over. Fasting lipid profiles, ambulatory blood pressure, auxological data, body composition, activity levels, and three-day food records were collected at baseline and after each 6-week intervention. Insulin sensitivity was measured by the Matsuda method using glucose and insulin values from an oral glucose tolerance test. 45 subjects completed the study, and compliance was very high: 87% of participants took >80% of prescribed capsules. At baseline, 44% of subjects were overweight or obese. 28% had decreased insulin sensitivity, but none had impaired glucose tolerance. Fibre supplementation led to a 4% reduction in android fat to gynoid fat ratio (p = 0.019), as well as a 0.12 mmol/l (6%) reduction in LDL cholesterol (p = 0.042). No associated adverse events were recorded. Dietary supplementation with 6 g/day of psyllium over 6 weeks improves fat distribution and lipid profile (parameters of the metabolic syndrome) in an at risk population of adolescent males. Australian New Zealand Clinical Trials Registry ACTRN12609000888268.
Crude fiber (CF) is the residue of plant food left after extraction by dilute acid followed by dilute alkali. Dietary fiber (DF), a new term, is the residue of plant food resistant to hydrolysis by human alimentary enzymes. DF is composed of cellulose, hemicellulose, and lignin; these constituents are not reported in food tables. For instance, whole wheatmeal has DF about 11%, CF about 2%. It is suggested that a new term, dietary fiber complex (DFC), should include all substances of DF plus all chemical compounds naturally associated with, and concentrated around, these structural polymers. CF supplies from starchy staples, wheat and potato, in England and Wales were probably stationary from 1770 to 1860, fell greatly from 1860 to 1910, rose during food controls in 1942 to 1953, and declined slightly from 1954 to 1970. It is postulated that fiber is a protective factor against certain colonic disorders, such as diverticular disease, and certain metabolic diseases, such as ischemic heart disease, diabetes mellitus, and obesity. These three diseases had changing trends of mortality rates in England during the food control years. Westernization of African diets is accompanied by a large fall in CF from starchy foods and vegetables and an increased prevalence of the same three diseases.
The authors conducted a double-blind clinical evaluation of the combination treatment of Psyllium husk with microencapsulated paraffin (Parapsyl®) versus placebo, aimed at evaluating the clinical and laboratorial efficacy and safety of this combination in the treatment of constipation. Sixty patients were recruited; of these, 30 received the combination treatment and 30 placebo. The study analyzed the state of constipation at the end of each week, with evaluation of efficacy based on the criteria of number of evacuations per week, improvement of the feces characteristics, and laboratory exams. In the combination group, normalization of evacuation was achieved in 25 patients on visit two, and in 26 patients on visit three. In the placebo group, 10 patients normalized evacuation on visit two, and nine on visit three. The number of unconstipated patients, at the last evaluation of the study, was significantly higher in the combination group (Psyllium/microencapsulated paraffin). There were no dropouts from combination group. The combination of Psyllium husk and microencapsulated paraffin was effective in 76.66% of the cases, with an efficiency rate of 81% (IC 95%: 0,51-0,93) (RR = 0,19, IC 95%: 0,07-0,49, p<0.001).
• The effects of the administration of 5.1 g of psyllium or placebo (cellulose) twice daily for 16 weeks were compared as adjuncts to a prudent diet in the management of moderate hypercholesterolemia in a parallel, double-blind study. Psyllium decreased the total cholesterol level by 5.6% and the low-density lipoprotein cholesterol level by 8.6%, whereas the levels were unchanged in the placebo group. The high-density lipoprotein cholesterol level decreased during the diet stabilization period in both groups and returned to near-baseline values by week 16. Plasma triglyceride levels did not change substantially in either group. Subject compliance to treatment was greater than 95%. These data suggest that psyllium hydrophilic mucilloid in a twice-daily regimen may be a useful and safe adjunct to a prudent diet in the treatment of moderate hypercholesterolemia. (Arch Intern Med. 1990;150:1822-1827)
Achieving adequate dietary fiber intake ADA recommends that health professionals: promote food intake patterns consistent with the Food Guide Pyramid (39) that make use of a wide variety of plant foods to achieve adequate fiber intakes in healthy children and adults. Include at least 2 to 3 servings of whole grains as part of the daily 6 to 11 servings of grains (40), 5 servings of fruits and vegetables daily, and legumes at least once or twice a week recognize that diets containing excess bulk may not contain sufficient energy to support normal growth in children recognize that 1 to 2 servings daily of higher fiber foods (eg, legumes, whole grains, cereal brans) or concentrated fiber sources may be necessary to achieve adequate intakes in those persons whose energy needs are low relative to body mass, such as the elderly, hospitalized or ill patients, or those in long-term- care facilities; consider the use of concentrated sources of dietary fiber(9) to treat chronic constipation when a limited variety of food is consumed or the amount of food consumed is inadequate: incorporate new sources of dietary fiber into diet plans for specific diseases only when benefit claims are documented and the overall diet is consistent with the medical nutrition therapy appropriate for the disease: recognize that viscous concentrated fiber sources with documented health benefits do have demonstrated blood cholesterol-lowering effects and can be part of lifestyle that includes a heart-healthy diet and exercise: use a diet pattern for persons with diabetes mellitus that is moderate in fat and contains a wide variety of fiber- containing foods to lower abnormal elevations in postprandial blood glucose levels and promote body weight normalization: use enteral feedings containing dietary fiber to promote normal enterocyte function, but recognize that clinical benefits may be modest.
Irritable bowel syndrome (IBS) is the most common disorder diagnosed by gastroenterologists and one of the more common ones encountered in general practice. The overall prevalence rate is similar (approximately 10%) in most industrialized countries; the illness has a large economic impact on health care use and indirect costs, chiefly through absenteeism. IBS is a biopsychosocial disorder in which 3 major mechanisms interact: psychosocial factors, altered motility, and/or heightened sensory function of the intestine. Subtle inflammatory changes suggest a role for inflammation, especially after infectious enteritis, but this has not yet resulted in changes in the approach to patient treatment. Treatment of patients is based on positive diagnosis of the symptom complex, limited exclusion of underlying organic disease, and institution of a therapeutic trial. If patient symptoms are intractable, further investigations are needed to exclude specific motility or other disorders. Symptoms fluctuate over time; treatment is often restricted to times when patients experience symptoms. Symptomatic treatment includes supplementing fiber to achieve a total intake of up to 30 g in those with constipation, those taking loperamide or other opioids for diarrhea, and those taking low-dose antidepressants or infrequently using antispasmodics for pain. Older conventional therapies do not address pain in IBS. Behavioral psychotherapy and hypnotherapy are also being evaluated. Novel approaches include alosetron; a 5-HT3 antagonist, tegaserod, a partial 5-HT4 agonist, κ-opioid agonists, and neurokinin antagonists to address the remaining challenging symptoms of pain, constipation, and bloating. Understanding the brain-gut axis is key to the eventual development of effective therapies for IBS.
This literature review and the recommendations therein were prepared for the American Gastroenterological Association Clinical Practice and Practice Economics Committee. The paper was approved by the Committee on March 4, 2000, and by the AGA Governing Board on May 21, 2000. GASTROENTEROLOGY 2000;119:1766-1778
Constipation is a common symptom that may be idiopathic or due to various identifiable disease processes. Laxatives are agents that add bulk to intestinal contents, that retain water within the bowel lumen by virtue of osmotic effects, or that stimulate intestinal secretion or motility, thereby increasing the frequency and ease of defecation. Drugs which improve constipation by stimulating gastrointestinal motility by direct actions on the enteric nervous system are under development. Other modalities used to treat constipation include biofeedback and surgery. Laxatives and lavage solutions are also used for colon preparation and evacuation of the bowels after toxic ingestions.