Restitution of gut microbiota in Ugandan children administered with probiotics (Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12) during treatment for severe acute malnutrition

The infant gut microbiome and cognitive development in malnutrition

Malnutrition affects 195 million children under the age of five worldwide with long term effects that include impaired cognitive development. Brain development occurs rapidly over the first 36 months of life. Whilst seemingly independent, changes to the brain and gut microbiome are linked by metabolites, hormones, and neurotransmitters as part of the gut-brain axis. In the context of severe malnutrition, the composition of the gut microbiome and the repertoire of biochemicals exchanged via the gut-brain axis vary when compared to healthy individuals. These effects are primarily due to the recognized interacting determinants, macro- and micronutrient deficiencies, infection, infestations and toxins related to poor sanitation, and a dearth of psycho-social stimulation. The standard of care for the treatment of severe acute malnutrition is focused on nutritional repletion and weight restoration through the provision of macro- and micronutrients, the latter usually in excess of recommended dietary allowances (RDA). However, existing formulations and supplements have not been designed to specifically address key recovery requirements for brain and gut microbiome development. Animal model studies indicate that treatments targeting the gut microbiome could improve brain development. Despite this, research on humans targeting the gut microbiome with the aim of restoring brain functionality are scarce. We conclude that there is a need for assessment of cognition and the use of various tools that permit visualization of the brain anatomy and function (e.g., Magnetic resonance imaging (MRI), functional near-infrared spectroscopy (fNIRS), electroencephalogram (EEG)) to understand how interventions targeting the gut microbiome impact brain development.

Gut Microbiome-Targeted Nutrition Interventions and Growth among Children in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Background

Childhood malnutrition is a public health challenge of much interest and concern globally. However, a perturbed gut microbiome (GM) may limit some nutrition interventions' effects among healthy children with undernutrition.

Objectives

This review aimed to evaluate the effects of GM-targeted nutrition interventions on growth outcomes among children (0-59 mo) using published studies in low- and middle-income countries.

Methods

The methods were guided by the Cochrane methodology. The literature search was conducted to include articles published from inception to July 2023 in PubMed, Google Scholar, and Cochrane Databases. We identified and included 35 studies among 11,047 children. The analysis was conducted considering various growth parameters in the qualitative synthesis and weight gain (kg) in the meta-analysis.

Results

In the qualitative synthesis, 55.6% of prebiotics, 66.7% of probiotics, 71.4% of synbiotics, and 28.6% of "microbiome complementary feed" studies had significant effects on growth outcomes. Also, prebiotics had more studies with significant effects among healthy children, whereas probiotics, synbiotics, and "microbiome complementary feeds" had more studies with significant effects among children with undernutrition. Nineteen studies were included in the meta-analyses, of which 7 (36.8%) measured GM outcomes. The meta-analysis showed that prebiotics exhibited heterogeneity but had significant effects on weight in the intervention as compared with the control (mean difference [MD]: 0.14 kg; 95% CI: 0.02, 0.25; I2 = 63%, P = 0.02; 4 studies, n = 932). Probiotics had significant effects on weight in the intervention (MD: 0.15 kg; 95% CI: 0.06, 0.25; I2 = 42%, P = 0.05; 8 studies, n = 2437) as compared to the control. However, synbiotics (MD: 0.26 kg; 95% CI: -0.04, 0.56; I2 = 41%, P = 0.17; 4 studies, n = 1896] and "microbiome complementary feed" (MD: -0.03 kg; 95% CI: -0.18, 0.11; I2 = 0%, P = 0.60; 3 studies, n = 733] had no significant effects on weight in the intervention as compared with control.

Conclusions

Although probiotics and synbiotics may be effective at enhancing growth among children, the selection of interventions should be contingent upon health status.This trial was registered at www.crd.york.ac.uk/prospero/ as CRD42023434109.

Aminopeptidase O Protein mediates the association between Lachnospiraceae and appendicular lean mass

Objective

Investigating the causal relationship between Lachnospiraceae and Appendicular lean mass (ALM) and identifying and quantifying the role of Aminopeptidase O Protein (AOPEP) as a potential mediator.

Methods

The summary statistics data of gut microbiota composition from the largest available genome-wide association study (GWAS) meta-analysis conducted by the MiBioGen Consortium (n = 13,266). Appendicular lean mass data were obtained from the UK-Biobank (n = 450,243). We conducted bidirectional two-sample Mendelian randomization (MR) analysis using summary-level data from GWAS to investigate the causal relationship between Lachnospiraceae and ALM. Additionally, we employed a drug-targeted MR approach to assess the causal relationship between AOPEP and ALM. Finally, a two-step MR was employed to quantitatively estimate the proportion of the effect of Lachnospiraceae on ALM that is mediated by AOPEP. Cochran's Q statistic was used to quantify heterogeneity among instrumental variable estimates.

Results

In the MR analysis, it was found that an increase in genetically predicted Lachnospiraceae [OR = 1.031, 95% CI (1.011-1.051), P = 0.002] is associated with an increase in ALM. There is no strong evidence to suggest that genetically predicted ALM has an impact on Lachnospiraceae genus [OR = 1.437, 95% CI (0.785-2.269), P = 0.239]. The proportion of genetically predicted Lachnospiraceae mediated by AOPEP was 34.2% [95% CI (1.3%-67.1%)].

Conclusion

Our research reveals that increasing Lachnospiraceae abundance in the gut can directly enhance limb muscle mass and concurrently suppress AOPEP, consequently mitigating limb muscle loss. This supports the potential therapeutic modulation of gut microbiota for sarcopenia. Interventions such as drug treatments or microbiota transplantation, aimed at elevating Lachnospiraceae abundance and AOPEP inhibition, synergistically improve sarcopenia in the elderly, thereby enhancing the overall quality of life for older individuals.

Inflammation: the driver of poor outcomes among children with severe acute malnutrition?

Severe acute malnutrition (SAM) is the most life-threatening form of undernutrition and underlies at least 10% of all deaths among children younger than 5 years in low-income countries. SAM is a complex, multisystem disease, with physiological perturbations observed in conjunction with the loss of lean mass, including structural and functional changes in many organ systems. Despite the high mortality burden, predominantly due to infections, the underlying pathogenic pathways remain poorly understood. Intestinal and systemic inflammation is heightened in children with SAM. Chronic inflammation and its consequent immunomodulation may explain the increased morbidity and mortality from infections in children with SAM, both during hospitalization and in the longer term after discharge. Recognition of the role of inflammation in SAM is critical in considering new therapeutic targets in this disease, which has not seen a transformational approach to treatment for several decades. This review highlights the central role of inflammation in the wide-ranging pathophysiology of SAM, as well as identifying potential interventions that have biological plausibility based on evidence from other inflammatory syndromes.

Malnourished Microbes: Host-Microbiome Interactions in Child Undernutrition

Childhood undernutrition is a major global health burden that is only partially resolved by nutritional interventions. Both chronic and acute forms of child undernutrition are characterized by derangements in multiple biological systems including metabolism, immunity, and endocrine systems. A growing body of evidence supports a role of the gut microbiome in mediating these pathways influencing early life growth. Observational studies report alterations in the gut microbiome of undernourished children, while preclinical studies suggest that this can trigger intestinal enteropathy, alter host metabolism, and disrupt immune-mediated resistance against enteropathogens, each of which contribute to poor early life growth. Here, we compile evidence from preclinical and clinical studies and describe the emerging pathophysiological pathways by which the early life gut microbiome influences host metabolism, immunity, intestinal function, endocrine regulation, and other pathways contributing to child undernutrition. We discuss emerging microbiome-directed therapies and consider future research directions to identify and target microbiome-sensitive pathways in child undernutrition.

A Scoping Review Evaluating the Current State of Gut Microbiota Research in Africa

The gut microbiota has emerged as a key human health and disease determinant. However, there is a significant knowledge gap regarding the composition, diversity, and function of the gut microbiota, specifically in the African population. This scoping review aims to examine the existing literature on gut microbiota research conducted in Africa, providing an overview of the current knowledge and identifying research gaps. A comprehensive search strategy was employed to identify relevant studies. Databases including MEDLINE (PubMed), African Index Medicus (AIM), CINAHL (EBSCOhost), Science Citation index (Web of Science), Embase (Ovid), Scopus (Elsevier), WHO International Clinical Trials Registry Platform (ICTRP), and Google Scholar were searched for relevant articles. Studies investigating the gut microbiota in African populations of all age groups were included. The initial screening included a total of 2136 articles, of which 154 were included in this scoping review. The current scoping review revealed a limited number of studies investigating diseases of public health significance in relation to the gut microbiota. Among these studies, HIV (14.3%), colorectal cancer (5.2%), and diabetes mellitus (3.9%) received the most attention. The top five countries that contributed to gut microbiota research were South Africa (16.2%), Malawi (10.4%), Egypt (9.7%), Kenya (7.1%), and Nigeria (6.5%). The high number (n = 66) of studies that did not study any specific disease in relation to the gut microbiota remains a gap that needs to be filled. This scoping review brings attention to the prevalent utilization of observational study types (38.3%) in the studies analysed and emphasizes the importance of conducting more experimental studies. Furthermore, the findings reflect the need for more disease-focused, comprehensive, and population-specific gut microbiota studies across diverse African regions and ethnic groups to better understand the factors shaping gut microbiota composition and its implications for health and disease. Such knowledge has the potential to inform targeted interventions and personalized approaches for improving health outcomes in African populations.

Gut microbiota and transcriptome dynamics in every-other-day fasting are associated with neuroprotection in rats with spinal cord injury

Introduction

Every-other-day fasting (EODF) is a classical intermittent fasting (IF) mode with neuroprotective effects that promotes motor function recovery after spinal cord injury (SCI) in rats. However, its dynamic effects on the gut microbiota and spinal cord transcriptome remain unknown.

Methods

In this study, 16S rRNA sequencing and RNA-seq analysis were used to investigate the effects of ad libitum (AL) and EODF dietary modes on the structural characteristics of rat gut microbiota in rats and the spinal cord transcriptome at various time points after SCI induction.

Results

Our results showed that both dietary modes affected the bacterial community composition in SCI rats, with EODF treatment inducing and suppressing dynamic changes in the abundances of potentially anti-inflammatory and pro-inflammatory bacteria. Furthermore, the differentially expressed genes (DEGs) enriched after EODF intervention in SCI rats were associated with various biological events, including immune inflammatory response, cell differentiation, protein modification, neural growth, and apoptosis. In particular, significant spatiotemporal differences were apparent in the DEGs associated with neuroprotection between the EODF and AL interventions. These DGEs were mainly focused on days 1, 3, and 7 after SCI. The relative abundance of certain genera was significantly correlated with DEGs associated with neuroprotective effects in the EODF-SCI group.

Discussion

Our results showed that EODF treatment may exert neuroprotective effects by modulating the transcriptome expression profile following SCI in rats. Furthermore, gut microbiota may be partially involved in mediating these effects.

The Mechanism of Antimicrobial Activity of Conjugated Bile Acids against Lactic Acid Bacilli

The mechanism underlying antimicrobial activity of conjugated bile acids against strains of lactic acid bacilli is not well understood. The purpose of this study was to investigate two typical conjugated bile acids (glycochenodeoxycholic acid and taurochenodeoxycholic acid) for their mechanisms of antimicrobial activity against four strains of different species of lactic acid bacilli at the physiological pH of the small intestine of humans. The bacterial cell membrane integrity, transmembrane potential, and transmembrane pH gradient were examined using the fluorescence probes SYTO 9 plus propidium iodide, 3,3'-dipropylthiadicarbocyanine iodide, and 5(6)-carboxyfluorescein diacetate N-succinimidyl ester, respectively. The intracellular ATP levels were measured by the firefly luciferase-based bioluminescence method. It was found that the antimicrobial activity of conjugated bile acids against the strains of lactic acid bacilli is strain-specific, and glycochenodeoxycholic acid showed significantly greater antimicrobial activity than taurochenodeoxycholic acid against the strains of lactic acid bacilli. The conjugated bile acids inhibited the growth of strains of lactic acid bacilli by disrupting membrane integrity, dissipating transmembrane potential, reducing the transmembrane pH gradient, and depleting intracellular ATP. In conclusion, the antimicrobial activity of conjugated bile acids against lactic acid bacilli is a multifactorial phenomenon. This study will provide valuable information for developing strategies to improve the ability of lactic acid bacilli to tolerate bile in vivo.

Prolonged dysbiosis and altered immunity under nutritional intervention in a physiological mouse model of severe acute malnutrition

Severe acute malnutrition (SAM) is a multifactorial disease affecting millions of children worldwide. It is associated with changes in intestinal physiology, microbiota, and mucosal immunity, emphasizing the need for multidisciplinary studies to unravel its full pathogenesis. We established an experimental model in which weanling mice fed a high-deficiency diet mimic key anthropometric and physiological features of SAM in children. This diet alters the intestinal microbiota (less segmented filamentous bacteria, spatial proximity to epithelium), metabolism (decreased butyrate), and immune cell populations (depletion of LysoDC in Peyer's patches and intestinal Th17 cells). A nutritional intervention leads to a fast zoometric and intestinal physiology recovery but to an incomplete restoration of the intestinal microbiota, metabolism, and immune system. Altogether, we provide a preclinical model of SAM and have identified key markers to target with future interventions during the education of the immune system to improve SAM whole defects.

Longitudinal Analysis of the Intestinal Microbiota among a Cohort of Children in Rural and Urban Areas of Pakistan

The profile of the intestinal microbiota is known to be altered in malnourished young children in low- and middle-income countries. However, there are limited studies longitudinally evaluating the intestinal microbiota in malnourished young children in resource-limited settings over the first two years of life. In this longitudinal pilot study, we determined the effect of age, residential location, and intervention on the composition, relative abundance, and diversity of the intestinal microbiota in a representative sample of children under 24 months of age with no diarrhea in the preceding 72 h in the urban and rural areas of Sindh, Pakistan nested within a cluster-randomized trial evaluating the effect of zinc and micronutrients on growth and morbidity (ClinicalTrials.gov Identifier: NCT00705445). The major findings were age-related with significant changes in alpha and beta diversity with increasing age. There was a significant increase in the relative abundance of the Firmicutes and Bacteroidetes phyla and a significant decrease in that of the Actinobacteria and Proteobacteria phyla (p < 0.0001). There were significant increases in the relative abundances of the major genera Bifidobacterium, Escherichia/Shigella and Streptococcus (p < 0.0001), and no significant change in the relative abundance of Lactobacillus. Using the LEfSE algorithm, differentially abundant taxa were identified between children in the first and second years of age, between those residing in rural and urban areas, and those who received different interventions at different ages from 3 to 24 months. The numbers of malnourished (underweight, wasted, stunted) or well-nourished children at each age, in each intervention arm, and at urban or rural sites were too small to determine if there were significant differences in alpha or beta diversity or differentially abundant taxa among them. Further longitudinal studies with larger numbers of well-nourished and malnourished children are required to fully characterize the intestinal microbiota of children in this region.

Antibiotic use and resistance in children with severe acute malnutrition and human immunodeficiency virus infection

Severe acute malnutrition (SAM) and human immunodeficiency virus (HIV) infection underlie a major proportion of the childhood disease burden in low- and middle-income countries. These diseases commonly co-occur and lead to higher risk of other endemic infectious diseases, thereby compounding the risk of mortality and morbidity. The widespread use of antibiotics as treatment and prophylaxis in childhood SAM and HIV infections, respectively, has reduced mortality and morbidity but canlead to increasing antibiotic resistance. Development of antibiotic resistance could render future infections untreatable. This review summarises the endemic co-occurrence of undernutrition, particularly SAM, and HIV in children, and current treatment practices, specifically WHO-recommended antibiotic usage. The risks and benefits of antibiotic treatment, prophylaxis and resistance are reviewed in the context of patients with SAM and HIV and associated sub-populations. Finally, the review highlights possible research areas and populations where antibiotic resistance progression can be studied to best address concerns associated with the future impact of resistance. Current antibiotic usage is lifesaving in complicated SAM and HIV-infected populations; nevertheless, increasing baseline resistance and infection remain a significant concern. In conclusion, antibiotic usage currently addresses the immediate needs of children in SAM and HIV endemic regions; however, it is prudent to evaluate the impact of antibiotic use on resistance dynamics and long-term child health.

Fecal Microbiota Transplantation Could Improve Chronic Diarrhea in Cynomolgus Monkey by Alleviating Inflammation and Modulating Gut Microbiota

Chronic diarrhea is associated with enteric dysbiosis and provokes the overuse of antibiotics. Fecal microbiota transplantation (FMT) is a promising therapy, but it shows discrepant clinical efficacy. Bacterial colonization in recipients has been studied, although little is known about the role of gut fungi and Archaea after FMT. In this study, we evaluated the efficacy of human-derived FMT on spontaneous chronic diarrhea cynomolgus monkeys and revealed the effector mechanisms. We demonstrated that FMT can mitigate the appearance of diarrheal symptoms and inhibit the increase in interleukin-6, interleukin-8, interleukin-1β, and interferon-γ and the decrease in interleukin-10 in serum. We confirmed that FMT restored the disturbance of gut bacteria by reducing the relative abundances of potential pathogens, including Cloacibacillus porcorum, Desulfovibrio desulfuricans, Erysipelotrichaceae bacterium 5_2_54FAA, and Erysipelotrichaceae bacterium 21_3, and increasing the levels of Lactobacillus fermentum and Lactobacillus ruminis CAG_367 in diarrheal monkeys. The metabolic pathways of healthy and FMT monkeys' gut bacteria were enriched in amino acid metabolism, carbohydrate metabolism, and lipid metabolism, while the metabolic pathways of pre-FMT monkeys' gut bacteria were enriched in antibiotic production. Moreover, a higher Ascomycota/Basidiomycota ratio, higher Aspergillus levels, and lower Trichosporon asahii abundance were present in intestinal fungi after FMT. Although the abundance of the Archaea Methanosphaera stastmanae did not change significantly, it was inversely correlated with the anti-inflammatory factor IL-4 after FMT. These results support the further development and application of FMT for chronic diarrhea.

Early-life chemical exposome and gut microbiome development: African research perspectives within a global environmental health context

The gut microbiome of neonates, infants, and toddlers (NITs) is very dynamic, and only begins to stabilize towards the third year of life. Within this period, exposure to xenobiotics may perturb the gut environment, thereby driving or contributing to microbial dysbiosis, which may negatively impact health into adulthood. Despite exposure of NITs globally, but especially in Africa, to copious amounts and types of xenobiotics - such as mycotoxins, pesticide residues, and heavy metals - little is known about their influence on the early-life microbiome or their effects on acute or long-term health. Within the African context, the influence of fermented foods, herbal mixtures, and the delivery environment on the early-life microbiome are often neglected, despite being potentially important factors that influence the microbiome. Consequently, data on in-depth understanding of the microbiome-exposome interactions is lacking in African cohorts. Collecting and evaluating such data is important because exposome-induced gut dysbiosis could potentially favor disease progression.

Dietary Component-Induced Inflammation and Its Amelioration by Prebiotics, Probiotics, and Synbiotics

A balanced diet with many dietary components maintains immune homeostasis directly by interacting with innate and adaptive immune components or indirectly through gut microbiota and their metabolites. Dietary components may inhibit pro-inflammatory mediators and promote anti-inflammatory functions or vice versa. Western diets with imbalanced dietary components skew the immune balance toward pro-inflammation and induce intestinal inflammation, consequently leading to many intestinal and systemic inflammatory diseases like ulcerative colitis, Crohn's disease, irritable bowel syndrome, cardiovascular problems, obesity, and diabetes. The dietary component-induced inflammation is usually chronic in nature and frequently caused or accompanied by alterations in gut microbiota. Therefore, microbiome-targeted therapies such as probiotics, prebiotics and synbiotics hold great potentials to amend immune dysregulation and gut dysbiosis, preventing and treating intestinal and systemic inflammatory diseases. Probiotics, prebiotics and synbioitcs are progressively being added to foods and beverages, with claims of health benefits. However, the underlining mechanisms of these interventions for preventing and treating dietary component-induced inflammation are still not very clear. In addition, possibly ineffective or negative consequences of some probiotics, prebiotics and synbiotics call for stringent testing and regulation. Here, we will first briefly review inflammation, in terms of its types and the relationship between different dietary components and immune responses. Then, we focus on current knowledge about the direct and indirect effects of probiotics, prebiotics and synbiotics on intestinal and systemic inflammation. Understanding how probiotics, prebiotics and synbiotics modulate the immune system and gut microbiota will improve our strategies for preventing and treating dietary component-induced intestinal inflammation and inflammatory diseases.

Changes in gut microbiota composition with age and correlations with gut inflammation in rats

Increasing evidences indicate that gut microbiota composition is associated with multiple inflammatory diseases. However, little is known about how gut microbiota changes with age and correlations with gut inflammation at sexual maturity stage of healthy individuals. Elucidating the dynamic changes of gut microbiota in healthy individuals at the sexual maturity stage and correlations with gut inflammation can provide clues for early risk assessment of gut diseases at the sexual maturity stage. Here, the shift in gut bacteria and its relationship with gut inflammation at the sexual maturity stage were explored. Sprague–Dawley rats at the sexual maturity stage were used in this study. 16S rRNA gene sequencing was performed to decipher gut bacteria shifts from the 7th week to the 9th week, and enzyme-linked immunosorbent assay (ELISA) was used to measure gut inflammation and gut barrier permeability. We found an increase in bacterial richness with age and a decrease in bacterial diversity with age. The gut bacteria were primarily dominated by the phyla Firmicutes and Bacteroides and the genus Prevotella. The relative abundance of Firmicutes increased with age, and the relative abundance of Bacteroides decreased with age. There was a positive correlation between body weight and the Firmicutes:Bacteroides ratio. More and more gut microbiota participated in the host gut inflammation and barrier permeability regulation with age. Ruminococcus was the only gut bacteria participated in gut inflammation and barrier permeability regulation both in the 7th week and the 15th week. These results provide a better understanding of the relationship between gut bacteria and gut inflammation in sexually mature rats and show that Ruminococcus may be a potential indicator for early risk assessment of gut inflammation.

Gut Microbiota Modulation of Moderate Undernutrition in Infants through Gummy Lactobacillus plantarum Dad-13 Consumption: A Randomized Double-Blind Controlled Trial

Undernutrition is associated with gut microbiota unbalance, and probiotics are believed to restore it and improve gut integrity. A randomized double-blind controlled trial was conducted to evaluate the efficacy of gummy L. plantarum Dad-13 (10^8-9 CFU/3 g) to prevent the progression of severe undernutrition. Two groups of moderate undernutrition infants were involved in this study, namely the placebo (n = 15) and probiotics (n = 15) groups, and were required to consume the product for 50 days. 16S rRNA sequencing and qPCR were used for gut microbiota analysis, and gas chromatography was used to analyze Short-Chain Fatty Acid (SCFA). The daily food intake of both groups was recorded using food records. Our results revealed that the probiotic group had better improvements regarding the anthropometry and nutritional status. In addition, L. plantarum Dad-13 modulated the butyric acid-producing bacteria to increase and inhibit the growth of Enterobacteriaceae. This gut modulation was associated with the increment in SCFA, especially total SCFA, propionic, and butyric acid. The number of L. plantarum was increased after the probiotic intervention. However, L. plantarum Dad-13 was not able to change the alpha and beta diversity. Therefore, L. plantarum Dad-13 has been proven to promote the growth of beneficial bacteria.

Bifidobacterium animalis subsp. lactis BB-12 Has Effect Against Obesity by Regulating Gut Microbiota in Two Phases in Human Microbiota-Associated Rats

Bifidobacterium animalis subsp. lactis BB-12 (BB-12) is an extensively studied probiotics species, which has been reported to improve the human gut microbiota. This study aimed to confirm the effects of BB-12 on high-fat diet (HFD)-induced gut microbiota disorders. The probiotic BB-12 was consumed by human microbiota-associated rats and changes in gut microbiota were compared using next generation sequencing of the fecal samples collected from the normal chow group, the HFD group, and the BB-12-supplemented group. The enterotypes switched from Prevotella dominant to Akkermansia dominant as a result of switching diet from normal chow to HFD. BB-12 conferred protection on the gut microbiota composition of the rats by increasing the abundance of Prevotella and decreasing the abundance of Clostridium, Blautia, and Bacteroides in 0-3 weeks. In addition, Prevotella-dominant enterotype was maintained, which provides improve obesity effects. A decrease in body weight and the Firmicutes/Bacteroidetes ratio were also observed at week 3. While in 4-8 weeks, the enrichment of short-chain fatty acids-producing bacteria such as Eubacterium and Parabacteroides and probiotics such as Bifidobacterium was observed. The results revealed that BB-12 against obesity by regulating gut microbiota in two phases. After a short-term intervention, BB-12 supplementation suppressed the transition from the healthy to obesity state by protecting Prevotella-dominant enterotype, whereas after a long-term intervention, BB-12 ameliorates obesity by enriching beneficial bacteria in the gut.

Efficacy of probiotics in the treatment of acute diarrhea in children: a systematic review and meta-analysis of clinical trials

BACKGROUND

If acute diarrhea in children is not treated promptly and effectively, it can lead to severe dehydration and serious sequelae. Due to the imbalance of intestinal bacteria in children with acute diarrhea, the supplementation with probiotics is important, which can improve the intestinal microenvironment, promote immunity, and enhance resistance. This meta-analysis provides further evidence and discussion of the therapeutic effect of probiotics on acute diarrhea in children.

METHODS

MEDLINE, EMBASE, PubMed, and the Cochrane Library databases were searched by rapid matching. The input keywords were as follows: (probiotics/synbiotics) and (child/children) and (acute diarrhea/acute gastroenteritis). Articles reporting on randomized controlled trials (RCTs) of probiotics in treating acute diarrhea in children were retrieved. The studies were published from 2010 to 2020. After screening and quality evaluation, Stata 16.0 software was used for the analysis.

RESULTS

Twelve articles with 744 patients were included in the study, and the overall quality of the articles was excellent. Meta-analysis showed that the duration of diarrhea in the probiotics group was shorter than that in the control group [standard mean difference (SMD) =-0.74, 95% CI: -1.11 to -0.37, Z=-3.935, P=0.000], the 2-day treatment efficacy for diarrhea in the probiotics group was greater than that in the control group [odds ratio (OR) =2.12, 95% CI: 1.47-3.05, Z=3.998, P=0.000], and the length of hospital stay in the probiotics group was shorter than that of the control group (SMD =-0.60, 95% CI: -0.74 to -0.47, Z=-8.781, P=0.000). In the subgroup analysis, combined probiotics shortened the duration of diarrhea compared with single probiotic use, and Lactobacillus reuteri and Saccharomyces boulardii had a better therapeutic effect than Lactobacillus rhamnosus or Lactobacillus acidophilus.

DISCUSSION

In the treatment of acute diarrhea in children, the addition of probiotics can shorten the duration of diarrhea, increase treatment efficacy after 2 days of treatment, and shorten the length of hospital stay. However, because of possible publication bias in the current study, further high-quality RCT studies in clinical settings are needed to verify the current results and continue the exploration of this topic.

Gut Microbiota-Targeted Nutritional Interventions Improving Child Growth in Low- and Middle-Income Countries: A Systematic Review

The objective of this systematic literature review was to evaluate the efficacy of probiotic, prebiotic, and synbiotic interventions compared with control on improving growth outcomes of children living in low- and middle-income countries (LMICs). Probiotics had a beneficial effect on ≥1 of the growth outcomes in 5 out of the 11 included studies. Of these, 3 studies were conducted in undernourished children, 1 in healthy children, and 1 in children without a described health status. No effect of prebiotics on growth outcomes was seen in the 4 included studies. Synbiotics had a beneficial effect on growth outcomes in 3 out of 4 studies. Although a limited number of studies with high heterogeneity indicate that probiotics and synbiotics may have the potential to improve the growth of both undernourished and healthy children living in LMICs, more research is needed to confirm the observed effects. This review was registered at www.crd.york.ac.uk/prospero/ as CRD42020212998.

Malnutrition and the microbiome as modifiers of early neurodevelopment

Malnutrition refers to a dearth, excess, or altered differential ratios of calories, macronutrients, or micronutrients. Malnutrition, particularly during early life, is a pressing global health and socioeconomic burden that is increasingly associated with neurodevelopmental impairments. Understanding how perinatal malnutrition influences brain development is crucial to uncovering fundamental mechanisms for establishing behavioral neurocircuits, with the potential to inform public policy and clinical interventions for neurodevelopmental conditions. Recent studies reveal that the gut microbiome can mediate dietary effects on host physiology and that the microbiome modulates the development and function of the nervous system. This review discusses evidence that perinatal malnutrition alters brain development and examines the maternal and neonatal microbiome as a potential contributing factor.

Administration of Bovine Milk Oligosaccharide to Weaning Gnotobiotic Mice Inoculated with a Simplified Infant Type Microbiota

Bovine milk oligosaccharides (BMO) share structural similarity to selected human milk oligosaccharides, which are natural prebiotics for infants. Thus, there is a potential in including BMOs as a prebiotic in infant formula. To examine the in vivo effect of BMO-supplementation on the infant gut microbiota, a BMO-rich diet (2% w/w) was fed to gnotobiotic mice (n = 11) inoculated with an infant type co-culture and compared with gnotobiotic mice receiving a control diet (n = 9). Nuclear magnetic resonance metabolomics in combination with high-throughput 16S rRNA gene amplicon sequencing was used to compare metabolic activity and microbiota composition in different compartments of the lower gastrointestinal tract. BMO components were detected in cecum and colon contents, revealing that BMO was available for the gut bacteria. The gut microbiota was dominated by Enterobacteriaceae and minor abundance of Lactobacilliaceae, while colonization of Bifidobacteriaceae did not succeed. Apart from a lower E. coli population in cecum content and lower formate (in colon) and succinate (in colon and cecum) concentrations, BMO supplementation did not result in significant changes in microbiota composition nor metabolic activity. The present study corroborates the importance of the presence of bifidobacteria for obtaining microbial-derived effects of milk oligosaccharides in the gastrointestinal tract.

Gut bacterial profile in Indian children of varying nutritional status: a comparative pilot study

PURPOSE

Childhood malnutrition is a multifactorial disease, responsible for nearly half of all deaths in children under five. Lately, the probable association of a dysbiotic gut to malnutrition is also being eagerly investigated. The current study is an attempt to investigate this purported association through assessing the abundance of major gut bacterial phyla (Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria), probionts (Bifidobacteria and Lactobacillus), butyrogens (Faecalibacterium and Roseburia) and pathogens (Escherichia and Klebsiella).

METHODS

The study was conducted in the suburbs of Chandigarh, India in the year 2017. The children enrolled in the study were part of Anganwadis (Rural Child Care Centres) set up under Integrated Child Development Scheme (ICDS) of Government of India where community-based management approach is being widely used for treatment of malnutrition. We used qPCR based absolute quantification as well as the 16S rRNA amplicon sequencing approach for our study. The study population included 30 children in the age group of 2-5 years who were categorized into three groups Healthy, Moderate Acute Malnutrition (MAM) and Severe Acute Malnutrition (SAM), with 10 children in each group. The selection of participants was made based on Z scores. Further, statistical tools like the One-way ANOVA, PCA and PLSDA were employed to analyze and compare the gut bacterial profile.

RESULTS

Our investigation through the qPCR (Absolute quantification) approach revealed a significantly higher abundance of Actinobacteria in healthy, in comparison to children suffering from Severe Acute Malnutrition (SAM). Consequently, the same trend was also reflected with respect to Bifidobacterium, a prominent member of the Actinobacteria phylum. Conversely, a significant higher abundance of Lactobacillus with the diminishing nutritional status was recorded. Escherichia showed a significant higher abundance in healthy subjects compared to the malnourished; however, no such difference in abundance of Klebsiella was observed. The other target phyla [Bacteroidetes, Firmicutes and Proteobacteria] and genera (Faecalibacterium and Roseburia) showed differences in abundance; however, these were non-significant. Similarly, the bacterial taxonomy analysis of 16S rRNA gene amplicon sequencing data revealed the higher abundance of phylum Actinobacteria and its member Bifidobacterium with lower prevalence of Lactobacillus in healthy children.

CONCLUSION

The pattern of gut microbiota profile in malnourished subjects suggests a dysbiotic gut depleted in Bifidobacteria, a core member of the consortia of beneficial anaerobes of the healthy child gut.

Gut dysbiosis during early life: causes, health outcomes, and amelioration via dietary intervention

The colonization and maturation of gut microbiota (GM) is a delicate and precise process, which continues to influence not only infancy and childhood but also adulthood health by affecting immunity. However, many perinatal factors, including gestational age, delivery mode, antibiotic administration, feeding mode, and environmental and maternal factors, can disturb this well-designed process, increasing the morbidity of various gut dysbiosis-related diseases, such as type-1-diabetes, allergies, necrotizing enterocolitis, and obesity. In this review, we discussed the early-life colonization and maturation of the GM, factors influencing this process, and diseases related to the disruption of this process. Moreover, we focused on discussing dietary interventions, including probiotics, oligosaccharides, nutritional supplementation, and exclusive enteral nutrition, in ameliorating early-life dysbiosis and diseases related to it. Furthermore, possible mechanisms, and shortcomings, as well as potential solutions to the drawbacks of dietary interventions, were also discussed.

The gut microbiome stability is altered by probiotic ingestion and improved by the continuous supplementation of galactooligosaccharide

The stable gut microbiome plays a key role in sustaining host health, while the instability of gut microbiome also has been found to be a risk factor of various metabolic diseases. At the ecological and evolutionary scales, the inevitable competition between the ingested probiotic and indigenous gut microbiome can lead to an increase in the instability. It remains largely unclear if and how exogenous prebiotic can improve the overall gut microbiome stability in probiotic consumption. In this study, we used Lactobacillus plantarum HNU082 (Lp082) as a model probiotic to examine the impact of the continuous or pulsed supplementation of galactooligosaccharide (GOS) on the gut microbiome stability in mice using shotgun metagenomic sequencing. Only continuous GOS supplement promoted the growth of probiotic and decreased its single-nucleotide polymorphisms (SNPs) mutation under competitive conditions. Besides, persistent GOS supplementation increased the overall stability, reshaped the probiotic competitive interactions with Bacteroides species in the indigenous microbiome, which was also evident by over-abundance of carbohydrate-active enzymes (CAZymes) accordingly. Also, we identified a total of 793 SNPs arisen in probiotic administration in the indigenous microbiome. Over 90% of them derived from Bacteroides species, which involved genes encoding transposase, CAZymes, and membrane proteins. However, neither GOS supplementation here de-escalated the overall adaptive mutations within the indigenous microbes during probiotic intake. Collectively, our study demonstrated the beneficial effect of continuous prebiotic supplementation on the ecological and genetic stability of gut microbiomes.

Microbiota on biotics: probiotics, prebiotics, and synbiotics to optimize growth and metabolism

The early stages of the metagenomics era produced countless observational studies linking various human diseases to alterations in the gut microbiota. Only recently have we begun to decipher the causal roles that gut microbes play in many of these conditions. Despite an incomplete understanding of how gut microbes influence pathophysiology, clinical trials have tested empirically numerous microbiota-targeting therapies to prevent or treat disease. Unsurprisingly, these trials have yielded mixed results. Nonetheless, the consumer market for probiotics, prebiotics, and synbiotics continues to grow. This theme paper highlights recent discoveries of mechanisms underlying diet-microbial-host interactions as they pertain to growth and metabolism and discusses current and future applications of microbiota-targeting therapies in the context of child malnutrition as well as obesity and its metabolic comorbidities, including nonalcoholic fatty liver disease and cardiovascular disease. We also highlight current challenges and identify future directions to facilitate a more efficient and direct path to clinical impact.