Short-chain fatty acids and commensal microbiota in the faeces of severely malnourished children with cholera rehydrated with three different carbohydrates
Abstract
Short-chain fatty acids (SCFAs) liberated by fermentation of complex carbohydrates might stimulate water and salt absorption, and provide energy. The aim of the study was to assess the number and proportion of faecal bacteria and the concentration of SCFAs of severely malnourished children with cholera receiving oral rehydration solution (ORS) containing glucose, amylase-resistant starch (ARS) or rice.
Serial faecal samples were collected from 30 malnourished children with cholera until rehydration and partial nutritional recovery. SCFAs were identified and quantitated by high-performance liquid chromatography. In situ hybridization combined with flow cytometry was used to analyse the microbiota in the faeces.
Before treatment the concentration of total SCFA in faecal sample of cholera children was found to be 4.7±0.6 mmol/kg and it increased steadily until 95.0±8.7 mmol/kg at day 28. Among different ORS groups, concentration was significantly higher in the Rice-ORS group at day 1 (P<0.011) and at day 2 (P<0.025). During recovery faecal output was significantly reduced and the number of bacteria also increased faster in the Rice-ORS group than in the glucose-ORS group at day 1 and day 2 (P<0.01), and a modest increase in bacterial number was observed in the glucose-ORS plus ARS group (day 1, P=0.07; day 2, P=0.09).
Clinical recovery was associated with an increase in bacterial and SCFA concentrations with all three carbohydrates in ORS. However, the increases were significantly higher in children receiving Rice-ORS.
Supplementary resource (1)
... Sebelumnya, pada anak yang mengalami gizi kurang diketahui memiliki jumlah asam lemak rantai pendek yang rendah (Kamil et al., 2021a;Monira et al., 2010). Asam lemak rantai pendek sendiri berguna dalam menjaga kondisi hipoksia pada kolon, sehingga meningkatkan selektivitas terhadap bakteri patogen yang bersifat fakultatif anaerob (Li et al., 2020). ...
Background: Undernutrition, a high nutritional problem in Indonesia, can be caused by the imbalance of the gut microbiota composition and gut healthiness. Probiotic intervention is one of the ways that can maintain those aspects. Preventive steps to address malnutrition can improve human resources in the future. Objectives: This research aimed to evaluate the efficacy of probiotic L. plantarum Dad-13 intervention on fecal quality and gut microbiota modulation of undernourished infants. Methods: This research was conducted in Tirtoadi Village, Sleman, Yogyakarta, from January to March 2020, using a randomized, double-blind clinical control trial design with two groups: placebo (n:15) and probiotic (n:15), over a 50-day intervention period. The probiotic group was given L. plantarum Dad-13 candy, while the placebo group was given candy with the same composition but without adding L. plantarum Dad-13. Anthropometric measurements and feces sampling were carried out before and after the intervention. Fecal samples were then analyzed for fecal quality and intestinal microbial composition. The data obtained were analyzed using the Wilcoxon paired test for within-group differences (before and after the intervention). In contrast, the Wilcoxon rank-sum test was used for between-group analysis (placebo and probiotic). Results: The result showed that the intervention of L. plantarum Dad-13 candy improved defecation frequency (p<0,024) and fecal consistency towards the normal category. Besides that, although there is no change in the F/B ratio, L. plantarum Dad-13 intervention also enhanced the number of genus-related Firmicutes phylum, which have the benefit of maintaining gut health and inhibiting the growth of pathogenic bacteria. Conclusion: Therefore, probiotic L. plantarum Dad-13 can prevent the progression of stunting in undernourished children.
... Moreover, once V. cholerae established itself in the gut, it can also decrease the amount of SCFA by decreasing the amount of SCFA-producing gut commensals such as Bifidobacterium species. This was reported in a clinical surveillance sample, demonstrating the decrease in abundance of Bifidobacterium species during the infection, and the level is restored to normal as the treatment of the infection progresses [109]. You et al. reported that when mice were treated with antibiotics, such as clindamycin which clears the abundance of Bacteroides species, a decrease in the level of SCFA was observed and an enhanced colonization potential by V. cholerae [110]. ...
Vibrio cholerae is a non-invasive enteric pathogen known to cause a major public health problem called cholera. The pathogen inhabits the aquatic environment while outside the human host, it is transmitted into the host easily through ingesting contaminated food and water containing the vibrios, thus causing diarrhoea and vomiting. V. cholerae must resist several layers of colonization resistance mechanisms derived from the host or the gut commensals to successfully survive, grow, and colonize the distal intestinal epithelium, thus causing an infection. The colonization resistance mechanisms derived from the host are not specific to V. cholerae but to all invading pathogens. However, some of the gut commensal-derived colonization resistance may be more specific to the pathogen, making it more challenging to overcome. Consequently, the pathogen has evolved well-coordinated mechanisms that sense and utilize the anti-colonization factors to modulate events that promote its survival and colonization in the gut. This review is aimed at discussing how V. cholerae interacts and resists both host- and microbe-specific colonization resistance mechanisms to cause infection.
... The bloom of these bacteria is facilitated by the transiently oxygenated gut environment during diarrhea, evidenced by the respective elevation in genes encoding low-affinity cytochrome oxidases [18 ]. This increased abundance is coupled with a drastic disappearance of obligate anaerobic gut commensals (Blautia, Prevotella, Faecalibacterium, Lachnospiraceae, Ruminococcaceae, etc.) [14 ,15 ], leading to a depletion of associated metabolites such as short chain fatty acid (SCFAs) [22,23]. Diarrheagenic bacteria, however, are usually of transient and/or low abundance (except for Vibrio cholerae in the first day) [15 ,18 ,24]. ...
Despite the widespread implementation of sanitation, immunization and appropriate treatment, infectious diarrheal diseases still inflict a great health burden to children living in low resource settings. Conventional microbiology research in diarrhea have focused on the pathogen’s biology and pathogenesis, but initial enteric infections could trigger subsequent perturbations in the gut microbiome, leading to short-term or long-term health effects. Conversely, such pre-existing perturbations could render children more vulnerable to enteropathogen colonization and diarrhea. Recent advances in DNA sequencing and bioinformatic analyses have been integrated in well-designed clinical and epidemiological studies, which allow us to track how the gut microbiome changes from disease onset to recovery. Here, we aim to summarize the current understanding on the diarrheal gut microbiome, stratified into different disease stages. Furthermore, we discuss how such perturbations could have impacts beyond an acute diarrhea episode, specifically on the child’s nutritional status and the facilitation of antimicrobial resistance.
... The main target of gut microbiota modulation is to promote the growth of beneficial producing SCFA bacteria. Notably, children who suffered severe acute malnutrition (SAM), possess low SCFA containing in their fecal sample, mainly propionic and butyric acid (Monira et al., 2010;Pekmez et al., 2018). The three dominants SCFA detected in human intestine are acetic, propionic, and butyric acid, which have molar ratio 3:1:1. ...
Stunting has become a major concern in Indonesia since 30.8% of under-5-years old Indonesian children in 2018 suffer for it. Children who suffer from stunting have growth faltering and less intelligence capacity. In the long term, it will affect their adult life productivity and national human resources quality. Stunting represents a nutrient requirement for children are not achieved especially in 1000 first day of life. Despite a lot of various reason, lack nutrient intake and infectious disease are considered as the direct cause of stunting. Recent research has explored that microbe who cohabitate human intestinal can affect their host's health and nutritive status. The composition of gut microbiota is shown different between a healthy individual and stunted individual. Hence, there is a hypothesis that stunting can be alleviated by modulating the composition of gut microbiota. Various kind of edible mushroom can be found and has been part of the diet for several Indonesian. Not only mushroom contains high dietary fiber, vitamin, and mineral, but also several mushrooms are known for its immunomodulating effect. With plentiful prebiotic potential carbohydrates, like chitin, hemicellulose, β and α-glucans, mannans, xylans, and, galactans in mushroom, Mushrooms can act as prebiotics to modulate gut microbiota, and give health benefits to the host. This paper will present several shreds of evidence that edible mushroom has potency to become a source of prebiotic, affect gut microbiota composition, and prevent stunting. It also will show any obstacles in applying edible mushroom in an attempt of combating stunting, to give future research prospect in related studies. INTISARI Stunting telah menjadi hal yang patut diperhatikan bagi Indonesia, karena 30,8% balita di Indonesia mengalami stunting pada 2018. Stunting menyebabkan pertumbuhan dan perkembangan, terutama kapasistas inteligensi, anak menjadi tidak optimal. Di kemudian hari, stunting akan memengaruhi produktivitas anak tersebut di masa dewasanya hingga kualitas sumber daya manusia nasional. Stunting menunjukkan tidak tercukupinya kebutuhan nutrisi anak terutama pada 1.000 hari pertama kehidupannya, yang dapat disebabkan oleh berbagai faktor. Asupan nutrisi yang tidak mencukupi dan terkena penyakit menular menjadi penyebab langsung seorang anak mengalami stunting. Penelitian terkini telah mempelajari bahwa mikroorganisme yang menghuni saluran pencernaan manusia dapat memengaruhi kesehatan tubuh manusianya itu sendiri. Kemudian, ditemukan perbedaan komposisi jenis-jenis mikroorganisme pada usus manusia yang sehat dan yang mengalami stunting. Sehingga, terdapat hipotesis bahwa stunting dapat ditanggulangi dengan mengubah komposisi mikrobiota usus. Di Indonesia, berbagai jenis jamur pangan telah umum dikonsumsi. Jamur pangan tidak hanya mengandung serat pangan, vitamin dan mineral yang tinggi, namun juga telah dikenal memiliki efek immunomodulatory. Jamur pagan juga mengandung berbagai jenis karbohidrat yang berpotensi memiliki aktifitas prebiotik, seperti kitin, hemiselulosa, β-dan α-glukan, manan, xylan, dan galaktan. Sehingga jamur pangan dapat berpotensi memodulasi mikrobiota usus dan memberikan efek kesehatan terhadap tubuh manusia. Artikel ini akan menunjukkan beberapa kajian potensi prebiotik dari jamur pangan, potensinya dalam mengubah komposisi mikrobiota usus dan menanggulangi stunting. Artikel ini juga akan tantangan dalam penggunaan jamur pangan untuk menanggulangi stunting untuk memberikan potensi penelitian lebih lanjut di bidang ini.
... A lower fecal SCFA production was also observed in children with severe GR under the infection of gut pathogens. However, SCFA levels increased in parallel with fecal microbiota amount during recovery (Monira et al. 2010). Thus, it may be speculated that administration of SCFAs into the circulatory system has multiple functions to directly influence CNS, which can alleviate GR caused by neuroinflammation or gut dysbiosis. ...
Growth retardation (GR), which commonly occurs in childhood, is a major health concern globally. However, the specific mechanism remains unclear. It has been increasingly recognized that changes in the gut microbiota may lead to GR through affecting the microbiota-gut-brain axis. Microbiota interacts with multiple factors such as birth to affect the growth of individuals. Microbiota communicates with the nerve system through chemical signaling (direct entry into the circulation system or stimulation of enteroendocrine cells) and nervous signaling (interaction with enteric nerve system and vagus nerve), which modulates appetite and immune response. Besides, they may also influence the function of enteric glial cells or lymphocytes and levels of systemic inflammatory cytokines. Environmental stress may cause leaky gut through perturbing the hypothalamic-pituitary-adrenal axis to further result in GR. Nutritional therapies involving probiotics and pre-/postbiotics are being investigated for helping the patients to overcome GR. In this review, we summarize the role of microbiota in GR with human and animal models. Then, existing and potential regulatory mechanisms are reviewed, especially the effect of microbiota-gut-brain axis. Finally, we propose nutritional therapeutic strategies for GR by the intervention of microbiota-gut-brain axis, which may provide novel perspectives for the treatment of GR in humans and animals.
While emerging evidence highlights the significance of gut microbiome in gastrointestinal infectious diseases, treatments like Fecal Microbiota Transplantation (FMT) and probiotics are gaining popularity, especially for diarrhea patients. However, the specific role of the gut microbiome in different gastrointestinal infectious diseases remains uncertain. There is no consensus on whether gut modulation therapy is universally effective for all such infections. In this comprehensive review, we examine recent developments of the gut microbiome’s involvement in several gastrointestinal infectious diseases, including infection of Helicobacter pylori, Clostridium difficile, Vibrio cholerae, enteric viruses, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa Staphylococcus aureus, Candida albicans, and Giardia duodenalis. We have also incorporated information about fungi and engineered bacteria in gastrointestinal infectious diseases, aiming for a more comprehensive overview of the role of the gut microbiome. This review will provide insights into the pathogenic mechanisms of the gut microbiome while exploring the microbiome’s potential in the prevention, diagnosis, prediction, and treatment of gastrointestinal infections.
The gut microbiota represents a community of microorganisms (bacteria, fungi, archaea, viruses, and protozoa) that colonize the gut and are responsible for gut mucosal structural integrity and immune and metabolic homeostasis. The relationship between the gut microbiome and human health has been intensively researched in the past years. It is now widely recognized that gut microbial composition is highly responsible for the general health of the host. Among the diseases that have been linked to an altered gut microbial population are diarrheal illnesses and functional constipation. The capacity of probiotics to modulate the gut microbiome population, strengthen the intestinal barrier, and modulate the immune system together with their antioxidant properties have encouraged the research of probiotic therapy in many gastrointestinal afflictions. Dietary and lifestyle changes and the use of probiotics seem to play an important role in easing constipation and effectively alleviating diarrhea by suppressing the germs involved. This review aims to describe how probiotic bacteria and the use of specific strains could interfere and bring benefits as an associated treatment for diarrhea and constipation.
Background:
In cystic fibrosis (CF), pathophysiologic changes in the gastrointestinal tract lead to malnutrition and altered gut microbiome. Microbiome alterations have been linked to linear growth, gut inflammation and respiratory manifestations. Elucidating these gut microbiome alterations may provide insight into future nutritional management in CF.
Methods:
Infants were followed for 12-months at four sites in the United States (US-CF) and Australia (AUS-CF). 16S rRNA gene sequencing was performed on longitudinal stool samples. Associations between microbial abundance and age, antibiotic prophylaxis, malnutrition, and breast feeding were evaluated using generalized linear mixed models. Taxonomic and predictive functional features were compared between groups.
Results:
Infants with CF (N = 78) were enrolled as part of a larger study. AUS-CF infants had higher mean weight-for-age z-scores than US-CF infants (p = 0.02). A subset of participants (CF N = 40, non-CF disease controls N = 10) provided stool samples for microbiome analysis. AUS-CF infants had lower stool alpha diversity compared to US-CF infants (p < 0.001). AUS-CF infants had higher relative abundance of stool Proteobacteria compared to US-CF infants which was associated with antibiotic prophylaxis (p < 0.001). Malnutrition (weight-for-age <10th percentile) was associated with depleted Lactococcus (p < 0.001). Antibiotic prophylaxis (p = 0.002) and malnutrition (p = 0.012) were linked with predicted decreased activity of metabolic pathways responsible for short chain fatty acid processing.
Conclusions:
In infants with CF, gut microbiome composition and diversity differed between the two continents. Gut microbial diversity was not linked to growth. The relationship between malnutrition and antibiotic prophylaxis with reduced SCFA fermentation could have implications for gut health and function and warrants additional investigation.
Humans have been challenged by infectious diseases for all of their recorded history, and are continually being affected even today. Next-generation sequencing (NGS) has enabled identification of, i) culture independent microbes, ii) emerging disease-causing pathogens, and iii) understanding of the genome architecture. This, in turn, has highlighted that pathogen/s are not a monolith, and thereby allowing for the differentiation of the wide-ranging disease symptoms, albeit infected by a primary pathogen. The conventional ‘one disease - one pathogen’ paradigm has been positively revisited by considering limited yet important evidence of the co-presence of multiple transcriptionally active microbes (TAMs), potential pathogens, in various infectious diseases, including the COVID-19 pandemic. The ubiquitous microbiota presence inside humans gives reason to hypothesize that the microbiome, especially TAMs, contributes to disease etiology. Herein, we discuss current evidence and inferences on the co-infecting microbes particularly in the diseases caused by the RNA viruses - Influenza, Dengue, and the SARS-CoV-2. We have highlighted that the specific alterations in the microbial taxonomic abundances (dysbiosis) is functionally connected to the exposure of primary infecting pathogen/s. The microbial presence is intertwined with the differential host immune response modulating differential disease trajectories. The microbiota-host interactions have been shown to modulate the host immune responses to Influenza and SARS-CoV-2 infection, wherein the active commensal microbes are involved in the generation of virus-specific CD4 and CD8 T-cells following the influenza virus infection. Furthermore, COVID-19 dysbiosis causes an increase in inflammatory cytokines such as IL-6, TNF-α, and IL-1β, which might be one of the important predisposing factors for severe infection. Through this article, we aim to provide a comprehensive view of functional microbiomes that can have a significant regulatory impact on predicting disease severity (mild, moderate and severe), as well as clinical outcome (survival and mortality). This can offer fresh perspectives on the novel microbial biomarkers for stratifying patients for severe disease symptoms, disease prevention and augmenting treatment regimens.
A healthy development is denied to millions of children worldwide as harsh life conditions manifest themselves in an altered inflammation-prone microbiome crosstalk environment. Keynote of this tragedy is that insufficient nutritious amino acid blocks lipids-intake to sustain diverse microbiota, and promotes the generalist strategy followed by Escherichia coli -besides other proteobacteria- of shifting gut metabolism, subverting the site specificity of first immune reaction. Furthermore, it could be hypothesized that selective success lies in their ability to induce inflammation, since this phenomenon also fuels horizontal gene transfer (HGT). In this review, we dilucidate how immune mechanisms of environmental enteric dysfunction affect overgrowth restriction, infectious morbidity rate, and acquired lifelong risks among severe acute malnourished children. Also, despite acknowledging complexities of antimicrobial resistant enrichment, we explore and speculate over the links between virulence regulation and HGT as an indissociable part in the quest for new inflammatory niches by open genome bacteria, particularly when both collide in the most vulnerable.
A group-specific 16S rRNA-targeted oligonucleotide probe S-G-Lab-0158- a-A20 (Lab158) was designed and validated to quantify species of the phylogenetic group lactobacilli-enterococci. The Lab158 probe detects nearly all species of the genera Lactobacillus, Enterococcus, Pediococcus, Weissella, Vagococcus, Leuconostoc and Oenococcus. The specificity of the probe was tested on various species of the target group and on a range of common intestinal bacteria. For these experiments, procedures to permeabilize these groups of Gram-positive bacteria were optimized and fluorescent in situ hybridization (FISH) conditions for maximum specificity were determined. In addition, we showed that it is possible to distinguish the predominant gut- enterococci i.e. E, faecalis among the Lab158 probe-positive cells with the E. faecalis-specic probe Efs (1). Lactobacilli-enterococci in faecal samples of four Volunteers were enumerated by FISH using the Lab158 probe. With this technique 0.4-0.8 x 108 cells per gram wet weight of faeces were counted The Lab158 probe was also used to identify colonies after culturing faecal bacteria on MRS and Rogosa agar. Only 2% of the colonies hybridized to the lactobacilli-enterococci specific probe. Most of the remaining colonies hybridized to a bifidobacteria specific probe. This shows that FISH with probe Lab158 is a useful method to enumerate lactobacilli-enterococci in faeces and can assist in the identification of lactic acid bacteria grown on plates.
Three 16S rRNA hybridization probes were developed and tested for genus-specific detection of Bifidobacterium species in the human fecal flora. Variable regions V2, V4, and V8 of the 16S rRNA contained sequences unique to this genus and proved applicable as target sites for oligodeoxynucleotide probes. Determination of the genus specificity of the oligonucleotides was performed by whole-cell hybridization with fluorescein isothiocyanate-labelled probes. To this end, cells were fixed on glass slides, hybridized with the probes, and monitored by videomicroscopy. In combination with image analysis, this allowed quantification of the fluorescence per cell and objective evaluation of hybridization experiments. One of the probes developed was used to determine the population of Bifidobacterium spp. in human fecal samples. A comparison was made with results obtained by cultural methods for enumeration. Since both methods gave similar population estimates, it was concluded that all bifidobacteria in feces were culturable. However, since the total culturable counts were only a fraction of the total microscopic counts, the contribution of bifidobacteria to the total intestinal microflora was overestimated by almost 10-fold when cultural methods were used as the sole method for enumeration.
The frequent discrepancy between direct microscopic counts and numbers of culturable bacteria from environmental samples is just one of several indications that we currently know only a minor part of the diversity of microorganisms in nature. A combination of direct retrieval of rRNA sequences and whole-cell oligonucleotide probing can be used to detect specific rRNA sequences of uncultured bacteria in natural samples and to microscopically identify individual cells. Studies have been performed with microbial assemblages of various complexities ranging from simple two-component bacterial endosymbiotic associations to multispecies enrichments containing magnetotactic bacteria to highly complex marine and soil communities. Phylogenetic analysis of the retrieved rRNA sequence of an uncultured microorganism reveals its closest culturable relatives and may, together with information on the physicochemical conditions of its natural habitat, facilitate more directed cultivation attempts. For the analysis of complex communities such as multispecies biofilms and activated-sludge flocs, a different approach has proven advantageous. Sets of probes specific to different taxonomic levels are applied consecutively beginning with the more general and ending with the more specific (a hierarchical top-to-bottom approach), thereby generating increasingly precise information on the structure of the community. Not only do rRNA-targeted whole-cell hybridizations yield data on cell morphology, specific cell counts, and in situ distributions of defined phylogenetic groups, but also the strength of the hybridization signal reflects the cellular rRNA content of individual cells. From the signal strength conferred by a specific probe, in situ growth rates and activities of individual cells might be estimated for known species. In many ecosystems, low cellular rRNA content and/or limited cell permeability, combined with background fluorescence, hinders in situ identification of autochthonous populations. Approaches to circumvent these problems are discussed in detail.
To study the postprandial effects of changing the amylose-to-amylopectin ratio (Am:Ap) in the starch fraction of a meal, male volunteers were given hot mixed lunches ( 13% of energy as protein, 24% as fat, 6% as mono- and disaccharides, and 57% as polysaccharides) in which Am:Ap was either 0:100 or 45:55. The increase in Am:Ap resulted in a change in the shape of the glucose and insulin responses in the blood with significantly lower initial responses but a small increase for glucose and a decrease for insulin if averaged over the 6 h of the study. The rises in the concentration of free glycerol and free fatty acid that occurred after an initial drop were stronger at low Am:Ap. High-Am:Ap meals induced more satiety up to 6 h postprandially. There was no effect of Am:Ap on postprandial triacylglycerol in the blood or on breath hydrogen except for a weak trend toward a higher concentration at 6 h after the high-Am:Ap meals.
Six 16S rRNA-targeted oligonucleotide probes were designed, validated, and used to quantify predominant groups of anaerobic bacteria in human fecal samples. A set of two probes was specific for species of the Bacteroides fragilis group and the species Bacteroides distasonis. Two others were designed to detect species of the Clostridium histolyticum and the Clostridium lituseburense groups. Another probe was designed for the genera Streptococcus and Lactococcus, and the final probe was designed for the species of the Clostridium coccoides-Eubacterium rectale group. The temperature of dissociation of each of the probes was determined. The specificities of the probes for a collection of target and reference organisms were tested by dot blot hybridization and fluorescent in situ hybridization (FISH). The new probes were used in initial FISH experiments to enumerate human fecal bacteria. The combination of the two Bacteroides-specific probes detected a mean of 5.4 x 10(10) cells per g (dry weight) of feces; the Clostridium coccoides-Eubacterium rectale group-specific probe detected a mean of 7.2 x 10(10) cells per g (dry weight) of feces. The Clostridium histolyticum, Clostridium lituseburense, and Streptococcus-Lactococcus group-specific probes detected only numbers of cells ranging from 1 x 10(7) to 7 x 10(8) per g (dry weight) of feces. Three of the newly designed probes and three additional probes were used in further FISH experiments to study the fecal flora composition of nine volunteers over a period of 8 months. The combination of probes was able to detect at least two-thirds of the fecal flora. The normal biological variations within the fecal populations of the volunteers were determined and indicated that these variations should be considered when evaluating the effects of agents modulating the flora.
The human large intestine contains a microbiota, the components of which are generically complex and metabolically diverse. Its primary function is to salvage energy from carbohydrate not digested in the upper gut. This is achieved through fermentation and absorption of the major products, short chain fatty acids (SCFA), which represent 40–50% of the available energy of the carbohydrate. The principal SCFA, acetate, propionate and butyrate, are metabolized by the colonic epithelium (butyrate), liver (propionate) and muscle (acetate). Intestinal bacteria also have a role in the synthesis of vitamins B and K and the metabolism of bile acids, other sterols and xenobiotics.
The colonic microflora are also responsive to diet. In the presence of fermentable carbohydrate substrates such as non‐starch polysaccharides, resistant starch and oligosaccharides, bacteria grow and actively synthesize protein. The amount of protein synthesis and turnover within the large intestine is difficult to determine, but around 15 g biomass is excreted in faeces each day containing 1 g bacterial‐N. Whether bacterially synthesized amino acids are ever absorbed from the colon remains unclear.
Finally, individual colonic micro‐organisms such as sulphate‐reducing bacteria, bifidobacteria and clostridia, respond selectively to specific dietary components in a way that may be important to health.
A group-specific 16S rRNA-targeted oligonucleotide probe S-G-Lab-0158-a-A20 (Lab158) was designed and validated to quantify species of the phylogenetic group lactobacilli-enterococci. The Lab158 probe detects nearly all species of the genera Lactobacillus, Enterococcus, Pediococcus, Weissella, Vagococcus, Leuconostoc and Oenococcus. The specificity of the probe was tested on various species of the target group and on a range of common intestinal bacteria. For these experiments, procedures to permeabilize these groups of Gram-positive bacteria were optimized and fluorescent in situ hybridization (FISH) conditions for maximum specificity were determined. In addition, we showed that it is possible to distinguish the predominant gut-enterococci i.e. E. faecalis among the Lab158 probe-positive cells with the E. faecalis
Background
Acute diarrhoea is one of the principal causes of morbidity and mortality among children in low‐income countries. Glucose‐based ORS helps replace fluid and prevent further dehydration from acute diarrhoea. Since 2004, the World Health Organization has recommended the osmolarity < 270 mOsm/L (ORS ≤ 270 ) over the > 310 mOsm/L formulation (ORS ≥ 310). Glucose polymer‐based ORS (eg prepared using rice or wheat) slowly releases glucose and may be superior.
Objectives
To compare polymer‐based ORS with glucose‐based ORS for treating acute watery diarrhoea.
Search strategy
In September 2008, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL ( The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, LILACS, and m RCT. We also contacted researchers, organizations, and pharmaceutical companies, and searched reference lists.
Selection criteria
Randomized controlled trials of people with acute watery diarrhoea (cholera and non‐cholera associated) comparing polymer‐based and glucose‐based ORS (with identical electrolyte contents).
Data collection and analysis
Two authors independently assessed the search results and risk of bias, and extracted data. In multiple treatment arms with two or more treatment groups, we combined outcomes as appropriate and compared collectively with the control group.
Main results
Thirty‐four trials involving 4214 participants met the inclusion criteria: 27 in children, five in adults and two in both. Twelve trials used adequate methods to conceal allocation. Most compared polymer‐based ORS with ORS ≥ 310. There were fewer unscheduled intravenous infusions in the polymer‐based ORS group compared with glucose‐based ORS (ORS ≥ 310 and ≤ 270 groups combined) (RR 0.75, 95% CI 0.59 to 0.95; 2235 participants, 19 trials). Adults positive for Vibrio cholerae had a shorter duration of diarrhoea with polymer‐based ORS than with ORS ≤ 270 (MD ‐7.11 hours, SD ‐11.91 to ‐2.32; 228 participants, 4 trials). Wheat‐based ORS resulted in lower total stool output in the first 24 hours compared with ORS ≤ 270 (MD ‐119.85 g/kg, SD ‐114.73 to ‐124.97; 129 participants, 2 trials). Adverse effects were similar for polymer‐based ORS and glucose‐based ORS.
Authors' conclusions
Polymer‐based ORS shows some advantages compared to ORS ≥ 310 for treating all‐cause diarrhoea, and in diarrhoea caused by cholera. Comparisons favoured the polymer‐based ORS over ORS ≤ 270, but the analysis was underpowered. If specialists consider a potential role for polymer‐based ORS, further trials against the current standard (ORS ≤ 270) will be required.
Plain Language Summary
Polymer‐based oral rehydration solution (ORS) ORS for acute diarrhoea
Acute diarrhoea is a common cause of death and illness in developing countries. Oral rehydration solutions (ORS) have had a massive impact worldwide in reducing the number of deaths related to diarrhoea.
Most ORS is in the form of a sugar–salt solution, but over the years people have tried adding a variety of compounds ('glucose polymers') such as whole rice, wheat, sorghum, and maize. The aim is to slowly release glucose into the gut and improve the absorption of the water and salt in the solution. This review updates and expands on a 1998 Cochrane Review of rice‐based ORS, and assesses the available evidence on the use of polymer‐based ORS (both rice and non‐rice based) in comparison with the glucose‐based ORS.
The original ORS was based on glucose and had an osmolarity of ≥ 310 mOsm/L (ORS ≥ 310). Glucose‐based ORS with a lower osmolarity was later introduced in attempts to improve efficacy, and is considered better at reducing the amount and duration of diarrhoea.
Thirty‐four trials involving 4214 participants met the inclusion criteria: 27 in children; five in adults; and two in both. Most trials compared polymer‐based ORS with a sugar–salt ORS with a particular strength (ORS ≥ 310), which is slightly more salty than the currently agreed best formula (≤ 270 mOsm/L). The trials' methodological quality was variable.
Fewer people in the polymer‐based ORS group needed a drip to be rehydrated compared with those in the glucose‐based ORS group. Adverse events were similar for polymer‐based ORS and glucose‐based ORS.
The authors conclude that polymer‐based ORS show some advantages compared to glucose‐based ORS for treating diarrhoea of any cause and in diarrhoea caused by cholera. Limited evidence favoured the polymer‐based ORS over ORS ≤ 270.
Further trials should compare the efficiency of ORS ≤ 270 with a polymer‐based ORS.
Background:
Acute diarrhoea is one of the principal causes of morbidity and mortality among children in low-income countries. Glucose-based ORS helps replace fluid and prevent further dehydration from acute diarrhoea. Since 2004, the World Health Organization has recommended the osmolarity < 270 mOsm/L (ORS </= 270 ) over the > 310 mOsm/L formulation (ORS >/= 310). Glucose polymer-based ORS (eg prepared using rice or wheat) slowly releases glucose and may be superior.
Objectives:
To compare polymer-based ORS with glucose-based ORS for treating acute watery diarrhoea.
Search strategy:
In September 2008, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 3), MEDLINE, EMBASE, LILACS, and mRCT. We also contacted researchers, organizations, and pharmaceutical companies, and searched reference lists.
Selection criteria:
Randomized controlled trials of people with acute watery diarrhoea (cholera and non-cholera associated) comparing polymer-based and glucose-based ORS (with identical electrolyte contents).
Data collection and analysis:
Two authors independently assessed the search results and risk of bias, and extracted data. In multiple treatment arms with two or more treatment groups, we combined outcomes as appropriate and compared collectively with the control group.
Main results:
Thirty-four trials involving 4214 participants met the inclusion criteria: 27 in children, five in adults and two in both. Twelve trials used adequate methods to conceal allocation. Most compared polymer-based ORS with ORS >/= 310. There were fewer unscheduled intravenous infusions in the polymer-based ORS group compared with glucose-based ORS (ORS >/= 310 and </= 270 groups combined) (RR 0.75, 95% CI 0.59 to 0.95; 2235 participants, 19 trials). Adults positive for Vibrio cholerae had a shorter duration of diarrhoea with polymer-based ORS than with ORS </= 270 (MD -7.11 hours, SD -11.91 to -2.32; 228 participants, 4 trials). Wheat-based ORS resulted in lower total stool output in the first 24 hours compared with ORS </= 270 (MD -119.85 g/kg, SD -114.73 to -124.97; 129 participants, 2 trials). Adverse effects were similar for polymer-based ORS and glucose-based ORS.
Authors' conclusions:
Polymer-based ORS shows some advantages compared to ORS >/= 310 for treating all-cause diarrhoea, and in diarrhoea caused by cholera. Comparisons favoured the polymer-based ORS over ORS </= 270, but the analysis was underpowered. If specialists consider a potential role for polymer-based ORS, further trials against the current standard (ORS </= 270) will be required.
Assess the safety of rapid intravenous rehydration of severely malnourished children and compare the efficacy of 3 formulations of oral rehydration salts solutions.
A group of 175 severely malnourished children of either sex (weight/length <70% of National Center for Health Statistics median), ages 6 to 36 months with cholera, were randomly assigned to receive 1 of 3 oral rehydration solutions (ORSs): glucose-ORS (n=58), glucose-ORS plus 50 g/L of amylase-resistant starch (n=59), or rice-ORS (n=58). Severely dehydrated children at enrollment were administered 100 mL/kg of an intravenous solution for 4 to 6 hours before randomisation, and those with some dehydration were randomised on enrollment. The electrolytes of the 3 ORSs were identical. In acute and convalescence phases, treatment was similar other than the nature of the ORSs.
Intravenous fluid (mean) administered to 149 study children was 103 mL/kg (95% confidence interval [CI] 96-109), and all were rehydrated within 6 hours. None of them developed overhydration or heart failure. During the first 24 hours, stool output (31%; 95% CI 14%-42%; P=0.004) and the ORS intake (26%; 95% CI 12%-37%; P=0.002) of children receiving rice-ORS were significantly less compared with children receiving glucose-ORS. The mean duration of diarrhoea in all children (66 hours; 95% CI 62-71), and time to attain 80% of median weight/length (7.15+/-2.81 days) were not different.
Dehydration in severely malnourished children can safely be corrected within 6 hours. All study ORSs were equally efficient in correcting dehydration. Rice-ORS significantly reduced the stool output and ORS intake, confirming previous reports.