The intestinal bacterial colonisation in preterm infants: A review of the literature

Article (PDF Available)inClinical Nutrition 25(3):361-8 · July 2006with195 Reads
DOI: 10.1016/j.clnu.2006.03.002 · Source: PubMed
Abstract
The aim of this study is to review the normal development of the intestinal microflora of preterm infants and the factors influencing its development. Preterm infants have an increased intestinal permeability, which may lead to bacterial translocation to systemic organs and tissues. In combination with immaturity of the immune system the risk to systemic infections might be increased. Especially potential pathogenic bacteria are able to translocate. The intestinal microflora of breast-fed term infants, dominated by bifidobacteria and lactobacilli, is thought to suppress the growth of potentially pathogenic bacteria. Many attemps have been made to stimulate the presence of bifidobacteria and lactobacilli with changes in the diet and ingredients-like prebiotics and probiotics. After selection, six studies were included reviewing the intestinal bacterial colonisation of preterm infants. In general, these studies show that the intestinal bacterial colonisation with beneficial bacteria is delayed in preterm infants. The number of potentially pathogenic bacteria is high. Antibiotics influence the intestinal colonisation. Many preterm infants receive prophylactic antibiotics at birth. As antibiotics delay the normal intestinal colonisation, caution should be given to the treatment with broadspectrum antibiotics in preterm infants at birth and every attempt has to be made to restrict the period of treatment.
Clinical Nutrition (2006) 25, 361 368
REVIEW
The intestinal bacterial colonisation in preterm
infants: A review of the literature
Elisabeth A.M. Westerbeek
a
, Anemone van den Berg
a
, Harrie N. Lafeber
a
,
Jan Knol
b
, Willem P.F. Fetter
a
, Ruurd M. van Elburg
a,
a
Department of Pediatrics, Subdivision of Neonatology, VU University Medical Center, De Boelelaan 1117,
1081 HV Amsterdam, The Netherlands
b
Biomedical Research Department, Numico Research BV, Wageningen, The Netherlands
Received 10 January 2006; accepted 3 March 2006
KEYWORDS
Intestinal bacterial
colonisation;
Preterm infant;
Infant, very low birth
weight;
Enteral nutrition
Summary The aim of this study is to review the normal development of the
intestinal microﬂora of preterm infants and the factors inﬂuencing its development.
Preterm infants have an increased intestinal permeability, which may lead to
bacterial translocation to systemic organs and tissues. In combination with
immaturity of the immune system the risk to systemic infections might be increased.
Especially potential pathogenic bacteria are able to translocate. The intestinal
microﬂora of breast-fed term infants, dominated by biﬁdobacteria and lactobacilli,
is thought to suppress the growth of potentially pathogenic bacteria. Many attemps
have been made to stimulate the presence of biﬁdobacteria and lactobacilli with
changes in the diet and ingredients-like prebiotics and probiotics.
After selection, six studies were included reviewing the intestinal bacterial
colonisation of preterm infants. In general, these studies show that the intestinal
bacterial colonisation with beneﬁcial bacteria is delayed in preterm infants. The
number of potentially pathogenic bacteria is high. Antibiotics inﬂuence the
intestinal colonisation. Many preterm infants receive prophylactic antibiotics at
birth. As antibiotics delay the normal intestinal colonisation, caution should be given
to the treatment with broadspectrum antibiotics in preterm infants at birth and
every attempt has to be made to restrict the period of treatment.
& 2006 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All
rights reserved.
ARTICLE IN PRESS
http://intl.elsevierhealth.com/journals/clnu
0261-5614/\$ - see front matter & 2006 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
doi:10.1016/j.clnu.2006.03.002
Corresponding author. Tel.: +31 204442413; fax: +31 204443045.
E-mail address: rm.vanelburg@vumc.nl (R.M. van Elburg).
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362
Methods of literature review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363
Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364
Results of the literature search. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364
Characteristics of included studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364
Bacterial intestinal colonisation of preterm infants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Beneﬁcial bacteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Biﬁdobacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Lactobacilli. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Potentially pathogenic bacteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Enterobacteria, E. coli .................................................... 365
Bacteroides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Enterococci, Streptococci . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Pathogenic bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Clostridia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Staphylococci . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Pseudomonas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Klebsiella . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Conditions that modify intestinal bacterial microﬂora . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
Preterm versus term infants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
Breast-fed versus formula-fed infants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
Antibiotic versus no antibiotic treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
Vaginal delivery versus caesarean section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
Molecular techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
Introduction
The gastrointestinal tract is one of the largest
organs of the body serving as an important barrier
between ingested elements from the external
environment and the internal milieu of the body.
In children and adults, the intestine is able to
discriminate between pathogenic microorganisms
and the commensal intestinal microﬂora.
1
More-
over, it is able to select the beneﬁcial nutrients
from the ingested food. In the preterm infant,
these functions are not completed yet.
2,3
The
development of the intestinal microﬂora starts at
birth and is inﬂuenced by various factors such as
gestational age, mode of delivery, local environ-
ment, type of feeding, and antibiotic treatment.
48
In breast-f ed term infants, biﬁdobacteria become
the predominant bacteria in the intestinal micro-
ﬂora, whereas in formula-fed term infants the
intestinal micr oﬂora becomes more diverse with,
apart from biﬁdobacteria, also bacteroides, clos-
tridia, enterobacteria and streptococci.
911
There-
fore, therapies have focussed on the development
of a biﬁdogenic intestinal ﬂora, e.g. with prebiotics
and probiotics. Although recent studies with pre-
biotics and probiotics show promising results, more
studies are needed to determine the role of
prebiotics and probiotics in preterm infants.
1216
Bacteria in the lumen of the intestine can be
grouped according to their degree of pathogeni-
city.
17
Three groups of bacteria can be recognised:
(1) beneﬁcial, (2) potentially pathogenic and (3)
pathogenic bacteri a. Beneﬁcial effects are inhibi-
tion of growth of pathogenic bacteria, production
of vitamins, degrading and fermentation of food
ingredients, stimulation of feeding tolerance and
stimulation of immune functions. Pathogenic ef-
fects of bacteria include feeding intolerance,
inﬂammation, infections and especially in preterm
infants this can lead to necrotising enterocolitis.
Potentially pathogenic bacteria belong to the
normal microﬂora of the intestine, but may become
pathogenic if present in high numbers: enterobac-
teria, enterococci, Escheria coli, streptococci and
bacteroides. Potentially pathogenic bacteria-like
proteus, staphylococci, clostridia and klebsiella,
may become pathogenic, even if present in low
numbers.
2,17
Due to the immaturity of the gastrointestinal
tract, bacteria may translocate to systemic organs
and tissues and, in combination with immaturity of
the immune system, increase the risk for systemic
infections.
18
Especially potentially pathogenic bac-
teria have the potention to translocate.
19
An
intestinal microﬂora of anaerobic bacteria-like
biﬁdobacteria and lactobacilli favours protection,
ARTICLE IN PRESS
E.A.M. Westerbeek et al.362
because it may suppress the growth of pathogenic
bacteria.
20,21
Few studies have determined the developmental
aspects of the intesti nal bacterial colonisation of
preterm infants. As preterm infants often require
intensive care treatment with an increased risk for
serious infections, insight in the development of
the intestinal bacterial colonisation of (preterm)
infants is important. In addition, the various
potential factors inﬂuencing the intestinal bacter-
ial colonisation of these infants need to be studied.
It is not known whether prematurity itself may
inﬂuence the intestinal bacterial colonisation, but
preterm infants experience intensive care treat-
ment in their ﬁrst days of life and it is likely that
this inﬂuences the intestinal bacterial colonisation.
Preterm infants often need parenteral feeding, due
to the immaturity of their intestine and they often
need respiratory support, they are vulnerable for
infections and often require antibiotic treatment.
Increasing insight in the development of the
intestinal bacterial colonisation and the factors
involved might help to establish conditions in order
to alter a possibly pathogenic developmental micro-
ﬂora to that seen in healthy term infants. The aim of
this study is to review the normal development of
the intestinal microﬂora of preterm infants and the
factors inﬂuencing its development.
Methods of literature review
A literature search was performed by a PubMed
search from January 1970 till December 2005 using
the followi ng keywords and limits:
(Intestines[mesh] OR intestin* OR gut OR gastro-
intestin* OR enteric) and (ﬂora OR microbiolog* OR
microbiology[sh] OR microﬂora OR bacteria OR
bacterial OR ent erobacteria* OR colonisation OR
colonisation OR microbes OR microbial) and (neo-
nat* OR infant*) AND (premature OR preterm OR
pre-term OR low birth weight OR low weight OR
small for gestational age) and (english[la] OR
german[la] OR dutch[la]) NOT (Probiotics[mesh]
OR Oligosaccharides[mesh] OR prebiotic*[ti] OR
necrotising enterocolitis OR necrotic enteric colitis
OR ‘Enterocolitis, Necrotising’’[MeSH]).
Forward citation tracking was performed with
the retrieved publications via the Web of Science.
Related articles in PubMed and in the Web of
Science were reviewed as well as references
described in those publications.
Inclusion criteria:
preterm/very low birth weight (VLBW) infants
intestinal colonisation from birth
ARTICLE IN PRESS
Table 1 Included studies.
Author Year Population
(N)
Gestational age
(weeks)
Birth weight (g) Methods Purpose
Blakey et al.
23
1982 28 30 (2536) 1125 (5601500) Faeces culture ﬁrst 3
weeks
Identify micro-organisms colonising the gut of preterm
infants admitted to a special care nursery.
Stark and Lee
28
1982 26 33 (3035)
y
1920
y
(14402300)
Faeces culture ﬁrst 4
weeks
Deﬁne the early bacterial colonisation of the large
bowel of preterm infants fed expressed breast milk and
compare it to the colonisation of term infants who have
been breast or formula fed.
Rotimi et al.
25
1984 23 29 (2436) 1728 (7502400) Faeces culture ﬁrst 6
days
Investigate the development of bacterial colonisation
of preterm infants admitted to the special baby care
unit and whose mothers received antenatal care.
Sakata et al.
26
1985 13 29.5 (25.534.7) 1077 (8101350) Faeces culture ﬁrst 7
weeks
Investigate the development of the intestinal ﬂora in
VLBW infants in comparison with term infants.
Hall et al.
4
1990 98 32 (2533) 1140 (6202510) Faeces culture & gas
liquid chromatography
day 10 & 30
Determine whether a characteristic pattern of
colonisation with lactobacilli and biﬁdobacteria can be
identiﬁed in term and in preterm infants.
Gewolb et al.
24
1999 29 26 782 Faeces culture day 10, 20
&30
Serially characterise the aerobic and anaerobic stool
microﬂora in a cohort of preterm infants o1000 g at
birth.
Gestational age and birth weight are given as mean or median
y
(range).
The intestinal bacterial colonisation in preterm infants 363
Exclusion criteria:
necrotising enterocolitis
prebiotica/probiotica
The publications were analysed for:
1. Methods used for collecting and analysing the
faecal samples.
2. Investigation of bacterial intestinal colonisation
over time, collecting the faecal samples at least
once a week with precisely describing the day of
collection.
3. Availability of data on the number of infants (or
percentage) from whom bacteria were isolated.
4. Possible confounding factors, such as gestational
age, type of delivery, type of feeding, initiation
of feeding, antibiotic treatment, length of stay
at a NICU and obstetric diagnosis.
Results
Results of the literature search
With the initial search, 11 relevant publications
were found.
4,68,2228
The selected studies were published between
1979 and 2003. Five studies were excluded from
this review because of:
1. Unclear description of sampling.
8,22
2. Heterogeneity of the study population.
6,7
3. Lack of data on the number of infant s colonised
with tested bacteria.
27
Characteristics of included studies
Of the six selected studies, ﬁve studies used culturing
techniques on selective media to perform the
colonisation pattern. One study used culturing tech-
niques on selective media and gasliquid chromato-
graphy. Mean gestational age of the infants varied
from 26 weeks
24
to 33 weeks.
28
Mean birth weight of
the infants varied from 814
24
to 1920 g
28
(Tab le 1).
The included studies collected faecal samples at
different postnatal ages. For comparison, four
groups were deﬁned according to postnatal age at
sampling (Table 2):
1. within 48 h after birth;
2. day 59 (week 1);
ARTICLE IN PRESS
Table 2 Intestinal bacterial colonization at different postnatal ages.
o 2d 1wk 2wk 43wk o2d 1wk 2wk 43wk o2d 1wk 2wk 4 3wk
Beneﬁcial
Biﬁdobacteria Lactobacilli
Blakey ——— 7 8 14 25
Stark 0 55 63 ———
Rotimi 86 96 —— 13 14 ——
Sakata 0 43 100 100 0 0 14 80
Hall ——17 11 ——14 19
Gewolb ——44 ——44
Potentially pathogenic
Enterobacteria/E.coli Enterococci Bacteroides
Blakey 13 44 46 60 7 8 25 20 57 44 79 35
Stark ——— —— 40 64 38
Rotimi 78 100 —— X57 X91 —— X17 X78 ——
Sakata 100 100 100 100 100 100 100 100 14 14 29 43
Hall ——62 95 ——— ——
Gewolb ——14 43 ——X28 X57 ——10 10
Pathogenic
Clostridia Staphylococci Pseudomonas
Blakey X10 X20 X18 X35 X17 X20 X18 X35 0 12 11 0
Stark 20 56 25 ——— ——
Rotimi X44 X50
—— X48 X77 —— 49——
Sakata 0 0 29 57 43 71 86 100 0 29 14 29
Hall ——— —— ——
Gewolb ——— X59 X57 ——47
Data are expressed as percentage of the number of preterm infants with positive culture.
E.A.M. Westerbeek et al.364
3. day 1016 (week 2);
4. day 20 and more (Xweek 3).
Bacterial intestinal colonisation of
preterm infants
Beneﬁcial bacteria
Biﬁdobacteria
In ﬁve studies biﬁdobacteria were determined in
the faeces.
4,2426,28
In two of three studies,
biﬁdobacteria were not detected directly after
birth.
26,28
In these two studies, biﬁdobacteria
increased over time. In two studies, biﬁdobacteria
were rarely found during the whole study peri-
od.
4,24
In only one study, high numbers of biﬁdo-
bacteria were found also directly after birth.
25
In
conclusion, low numbers of biﬁdobacteria are
found in faeces of preterm infants.
Lactobacilli
In ﬁve studies, lactobacilli were determined in
the faeces.
4,2326
In none of the studies, lacto-
bacilli were found at birth. In the study of Sakata
et al.
26
lactobacilli growth increased after
2 weeks. In the other studies, lactobacilli growth
remained low.
4,23,25
In conc lusion, low numbers of
lactobacilli were found in the faeces of preterm
infants.
In summary, low numbers of beneﬁcial bacteria
are found in the intestinal microﬂora in preterm
infants.
Potentially pathogenic bacteria
Enterobacteria, E. coli
In ﬁve studies, enterobacteria were deter-
mined.
4,2326
In four studies analysing E. coli,
4,2325
E. coli was found in high numbers. In two studies,
enterobacteria were sparsely found.
24,25
In one
study, enterobacteria growth was rarely found
during the whol e study period.
18
The study of
Sakata et al.
26
analysed enterobacteria, without
further culturing of E. coli. Enterobacteria were
found in high numbers in all infants during the
whole study period. In conclusion, high numbers of
enterobacteria , E. coli are found in the faeces of
preterm infants.
Bacteroides
In ﬁve studies, Bacteroides was determined.
2325,28
In three studies, Bacteroides was found in high
numbers.
23,25,28
In one study Bacteroides growth
increased during the study period.
26
In one study,
Bacteroides was rarely found during the whole
study period.
24
In conclusion, high numbers of
Bacteroides are found in the faeces of preterm
infants.
Enterococci, Streptococci
In four studies, enterococci were determined.
2326
In two studies, strepto cocci were found in
high numbers during the whole study period.
25,26
In one study enterococci growth increased during
the study period.
24
In one study, enterococci were
23
In conclusion, high numbers of
enterococci are found in the faeces of preterm
infants.
In summary, high numbers of potentially patho-
genic bacteria are found in the intestinal microﬂora
of preterm infants.
Pathogenic bacteria
Clostridia
In ﬁve studies, clostridia were determined.
2326,28
In two studies clostridia were sparsely found.
23,24
In
two studies low numbers of clostridia were found in
the beginning of the study, but increased over
time.
26,28
In the study of Rotimi et al.
25
clostridia
were only found within 48 h. In conclusion, coloni-
sation with clostridia is diverse in the faeces of
preterm infants.
Staphylococci
In four studies, staphylococci were deter-
mined.
2326
In two studies, staphylococci were
sparsely found.
23,24
In the two other studies, high
numbers of staphylococci were found during the
whole study period.
25,26
In conclusion, high num-
bers of staphylococci are found in the faeces of
preterm infants.
Pseudomonas
In four studies, pseudomonas was determined.
2326
In all studies, pseudomonas was sparsely found. In
one study, pseudomonas growth increased slightly
over time.
26
In conclusion, low numbers of pseu-
domonas are found in the faeces of preterm
infants.
Klebsiella
In two studies, klebsiella were determined.
23,25
In
both studies, klebsiella growth increased over
time during the study. In conclusion, high numbers
of klebsiella are found in the faeces in preterm
infants
ARTICLE IN PRESS
The intestinal bacterial colonisation in preterm infants 365
In summary, high numbers of pathogenic bacteria
are found in the intestinal bacterial microﬂora of
preterm infants.
Conditions that modify intestinal bacterial
microﬂora
Preterm versus term infants
Three studies determined intestinal bacterial mi-
croﬂora in preterm and term infants.
4,26,28
In the
study of Sakata et al. enterobacteria and str epto-
cocci were dominant on day 1 in both groups. On
day 4, biﬁdobacteria became dominant in the term
group, whereas biﬁdobacteria became dominant on
day 20 in the VLBW infants group. The dominance
was weaker in the preterm group (ratio biﬁdobac-
teria to enterobacteria remained 10:1 at 7 weeks of
life) than in the term group (ratio 1000:1 on day
7).
26
In preterm infants, Stark and Lee
28
found that
colonisation with biﬁdobacteria was signiﬁcant
delayed during the ﬁrst week of life.
Hall et al.
4
found a signiﬁcantly lower prevalence
of colonisation with coliforms (Po0.01) and lacto-
bacilli (Po0.005) in the preterm group at 10 days.
At 30 days, there was a signiﬁcant lower prevalence
of lactobacilli in preterm infants (Po0.01).
Breast-fed versus formula-fed infants
One study compared the intestinal microﬂora of
breast-fed with formula-fed preterm infants.
24
In
the study of Gewolb et al. breast-fed infants
showed a more diverse bacterial population than
formula-fed infants with lower numbers of patho-
genic micr o-organisms.
Antibiotic versus no antibiotic treatment
Three studies determined the inﬂuence of anti-
biotic treatment on the intestinal bacterial coloni-
sation.
4,23,24
In the study of Gewolb et al. all
infants received at least 2 days of antibiotic
treatment during the ﬁrst month of life. They
found an inverse correlation between the number
of days of antibiotic treatment in the ﬁrst month of
life and the number of bacterial species (r ¼ 0.491;
P ¼ 0.007) and the to tal number of organisms
(r ¼ 0.482; P ¼ 0.008) in the faecal samples at
day 30. Only in one infant lactobacilli and biﬁdo-
bacteria were found.
24
Blakey et al.
23
found that in
infants receiving antibiotics after birth lactobacilli
were never isolated in the ﬁrst 20 days of life.
Before 12 days of age, clostridia were reduced in
infants receiving antibiotic treatment. At 10 days
of age, Hall et al.
4
found that infants treated
parenteral antibiotics had signiﬁcant reduced co-
lonisation rates of lactobacilli (Po0.01).
In summary, colonisation with bacteria, espe-
cially beneﬁcial bacteria like lactobacilli, is de-
layed in infants receiving antibiotics after birth.
Vaginal delivery versus caesarean section
Only one study determined the inﬂuence of method
of birth. Rotimi et al.
25
found that colonisation with
Bacteroides and clostridia is delayed in infants
delivered by caesarean section.
Molecular techniques
The studies discussed in this review used conven-
tional cultivating techniques to study the intestinal
microﬂora. In recent years molecular techniques
are developed for directly detecting different
groups of bacteria in faecal samples without
further cultivation.
29,30
However, only a few studies
used molecular techniques to study the intestinal
microﬂora in preterm infants.
27
Schwiertz et al.
27
to study the intestinal microﬂora of preterm
infants. They found an increase in similarity of
bacterial communities in hospitalised preterm
infants in contrast to breast-fed, term infant s on
the environment.
Discussion
Our review has shown that colonisation of biﬁdo-
bacteria and lactobacillus is delayed in preterm
infants, whereas colonisation with potentially
pathogenic bacteria (especially E. coli) is in-
creased. The type of feeding did not inﬂuence the
bacterial colonisation in preterm infants, but the
longer time to full enteral feeding may explain this
ﬁnding.
26
Early introduction of enteral feedings is thought
to stimulate the intestine of preterm infants. This
might maximise the immune functions of the
intestine, reduce the risk of infection and improve
the outcome of preterm infants. Prebiotics and
probiotics are thought to stimulate the presence of
a biﬁdogenic microﬂora and thus have a positive
effect on health.
1216
The intestinal micr oﬂora is difﬁcult to study. Only
a limited number of bac teria may be detecte d using
conventional cultivation techniques. Several stu-
dies show that ﬂuorescent in situ hybridisation
(FISH) analyses may provide quantitative data on
the relative amount of the different bacterial
groups, while cultivating techniques are insufﬁ-
ciently select ive and unsuitable for quantitative
analysis.
9,29,30
ARTICLE IN PRESS
E.A.M. Westerbeek et al.366
In this review, emphasis is put on studies using
conventional cultivation techniques and possibly
intestinal colonisation may differ from that in
studies using molecular techniques. Cultivation
techniques have a high sensitivity for E. coli,so
these studies may ﬁnd relatively high numbers of
E. coli. In this review, data are expressed as the
number of infants colonised with the speciﬁc
bacteria. This is not a sensitive metho d, because
every infant will be colonised with at least one
bacteria of every type of bacteria. Quantitat ive
data would be more reliable, but unfortuna tely
most studies in this review did not show these data.
The intestinal microﬂora has been implicated in
the pathogenesis of necrotising enterocolitis, which
is a signiﬁcant cau se of morbidity and mortality in
preterm infants. In this review, studies of patients
with necrotising enterocolitis were excluded, be-
cause pathoge nesis is multifactorial and speciﬁc
unrecognised bacteria might be involved, which are
not normally found in the intestine.
3133
It is concluded that the intestinal bacterial
colonisation with beneﬁcial bacteria is dela yed in
preterm infants, while the number of potentially
pathogenic bacteria is high. This review shows that
antibiotics may delay the normal intestinal coloni-
sation, caution should be given to the treatment
with broad spectrum antibiotics in preterm infants
at birth and every attempt has to be made to
restrict the period of treatment to a minimum.
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ARTICLE IN PRESS
E.A.M. Westerbeek et al.368
• Oropharyngeal colostrum in preventing mortality and morbidity in preterm infants
• "NEC is a complex process that involves inflammation and bacterial invasion of the immature mucosa. Hypoperfusion of the bowel, the use of antibiotics and delay to commence enteral feeding are factors that act synergistically to promote intestinal atrophy and abnormal bacterial colonization of the bowel (Rodriguez 2015; Westerbeek et al 2006). Late-onset infection (LOI), defined as a blood culture positive microbial infection after 72 hours of life (Stoll 2002), is associated with a high burden of morbidity and mortality in preterm infants. "
[Show description] [Hide description] DESCRIPTION: A Cochrane Protocol. Published : Cochrane Database of Systematic Reviews 2015, Issue 10
Full-text · Research · Feb 2016 · Journal of Pharmacy Practice and Research
• The New Era of Treatment for Obesity and Metabolic Disorders: Evidence and Expectations for Gut Microbiome Transplantation
• "The gut of preterm infants contains higher levels of C. difficile compared to full term infants (Penders et al., 2006). Moreover, data obtained from short-term stool culture have shown that colonization by Bifidobacterium and Lactobacillus is delayed in preterm infants, whereas colonization by potentially pathogenic bacteria (especially E. coli) is increased (Westerbeek et al., 2006; Butel et al., 2007). During infancy, diet is one of the many contributors to the development of gut microbiome (Koenig et al., 2011). "
[Show abstract] [Hide abstract] ABSTRACT: Key Points The microbiome has been implicated in the development of obesity. Conventional therapeutic methods have limited effectiveness for the treatment of obesity and prevention of related complications. Gut microbiome transplantation may represent an alternative and effective therapy for the treatment of obesity. Obesity has reached epidemic proportions. Despite a better understanding of the underlying pathophysiology and growing treatment options, a significant proportion of obese patients do not respond to treatment. Recently, microbes residing in the human gastrointestinal tract have been found to act as an “endocrine” organ, whose composition and functionality may contribute to the development of obesity. Therefore, fecal/gut microbiome transplantation (GMT), which involves the transfer of feces from a healthy donor to a recipient, is increasingly drawing attention as a potential treatment for obesity. Currently the evidence for GMT effectiveness in the treatment of obesity is preliminary. Here, we summarize benefits, procedures, and issues associated with GMT, with a special focus on obesity.
Full-text · Article · Feb 2016
• The effect of neutral oligosaccharides on fecal microbiota in premature infants fed exclusively with breast milk: A randomized clinical trial
• "] It has been found that the bifidobacteria and lactobacilli in preterm neonates are less compared with term neonates, while, the amount of potentially pathogenic bacteria in preterm neonates is more than that in term neonates. [3] Furthermore, prescription of antibiotics in preterm infants leads to a serious delay of GI colonization with bacteria. [4] In addition, in premature infants admitted to Neonatal Intensive Care Units (NICUs), the risk of neonatal infection is higher. [3] Although frequently serious infections in preterm infants are caused by coagulase‑negative staphylococci that come from external sources of infants, [3] in many cases, serious infections in newborns can be t"
Full-text · Article · Feb 2016
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