Abstract

BACKGROUND Microbial colonization of the gastrointestinal tract after birth is an essential event that influences infant health with life-long consequences. Therefore, it is important to investigate strategies to positively modulate colonization in early life. OBJECTIVES This randomized, controlled intervention study included 540 infants to investigate the effects of a synbiotic intervention formula (IF) containing Limosilactobacillus fermentum CECT5716 and galacto-oligosaccharides on the fecal microbiome. METHODS The fecal microbiota from infants was analyzed by 16S rRNA amplicon sequencing at 4, 12, and 24 months of age. Metabolites (e.g., short-chain fatty acids) and other milieu parameters (e.g., pH, humidity, and IgA) were also measured in stool samples. RESULTS Microbiota profiles changed with age, with major differences in diversity and composition. Significant effects of the synbiotic IF compared with control formula (CF) were visible at month 4, including higher occurrence of Bifidobacterium spp. and Lactobacillaceae and lower occurrence of Blautia spp., as well as Ruminoccocus gnavus and relatives. This was accompanied by lower fecal pH and concentrations of butyrate. After de novo clustering at 4 months of age, overall phylogenetic profiles of the infants receiving IF were closer to reference profiles of those fed with human milk than infants fed CF. The changes owing to IF were associated with fecal microbiota states characterized by lower occurrence of Bacteroides compared with higher levels of Firmicutes (valid name Bacillota), Proteobacteria (valid name Pseudomonadota), and Bifidobacterium at 4 months of age. These microbiota states were linked to higher prevalence of infants born by Cesarean section. CONCLUSIONS The synbiotic intervention influenced fecal microbiota and milieu parameters at an early age depending on the overall microbiota profiles of the infants, sharing a few similarities with breastfed infants. This trial was registered at clinicaltrials.gov as NCT02221687.

Abstract

Chronic constipation (CC) is a common gastrointestinal condition associated with intestinal inflammation, and the condition considerably impairs patients' quality of life. We conducted a large-scale 42-day randomized, double-blind, placebo-controlled trial to investigate the effect of probiotics in alleviating CC. 163 patients diagnosed with CC (following Rome IV criteria) were randomly divided into probiotic (n = 78; received Lactiplantibacillus plantarum P9 [P9]; 1 ×1011 CFU/day) and placebo (n = 85; received placebo material) groups. Ingesting P9 significantly improved the weekly mean frequency of complete spontaneous bowel movements (CSBMs) and spontaneous bowel movements (SBMs), while significantly reducing the level of worries and concerns (WO; P < 0.05). Comparing with the placebo group, P9 group was significantly enriched in potentially beneficial bacteria (Lactiplantibacillus plantarum and Ruminococcus_B gnavus), while depriving of several bacterial and phage taxa (Oscillospiraceae sp., Lachnospiraceae sp., and Herelleviridae; P < 0.05). Interesting significant correlations were also observed between some clinical parameters and subjects' gut microbiome, including: negative correlation between Oscillospiraceae sp. and SBMs; positive correlation between WO and Oscillospiraceae sp., Lachnospiraceae sp. Additionally, P9 group had significantly (P < 0.05) more predicted gut microbial bioactive potential involved in the metabolism of amino acids (L-asparagine, L-pipecolinic acid), short-/medium-chain fatty acids (valeric acid and caprylic acid). Furthermore, several metabolites (p-cresol, methylamine, trimethylamine) related to the intestinal barrier and transit decreased significantly after P9 administration (P < 0.05). In short, the constipation relief effect of P9 intervention was accompanied by desirable changes in the fecal metagenome and metabolome. Our findings support the notion of applying probiotics in managing CC.

Abstract

Probiotics have shown potential to counteract sarcopenia, although the extent to which they can influence domains of sarcopenia such as muscle mass and strength in humans is unclear. The aim of this systematic review and meta-analysis was to explore the impact of probiotic supplementation on muscle mass, total lean mass and muscle strength in human adults. A literature search of randomized controlled trials (RCTs) was conducted through PubMed, Scopus, Web of Science and Cochrane Library from inception until June 2022. Eligible RCTs compared the effect of probiotic supplementation versus placebo on muscle and total lean mass and global muscle strength (composite score of all muscle strength outcomes) in adults (>18 years). To evaluate the differences between groups, a meta-analysis was conducted using the random effects inverse-variance model by utilizing standardized mean differences. Twenty-four studies were included in the systematic review and meta-analysis exploring the effects of probiotics on muscle mass, total lean mass and global muscle strength. Our main analysis (k = 10) revealed that muscle mass was improved following probiotics compared with placebo (SMD: 0.42, 95% CI: 0.10-0.74, I2  = 57%, P = 0.009), although no changes were revealed in relation to total lean mass (k = 12; SMD: -0.03, 95% CI: -0.19 - 0.13, I2  = 0%, P = 0.69). Interestingly, a significant increase in global muscle strength was also observed among six RCTs (SMD: 0.69, 95% CI: 0.33-1.06, I2  = 64%, P = 0.0002). Probiotic supplementation enhances both muscle mass and global muscle strength; however, no beneficial effects were observed in total lean mass. Investigating the physiological mechanisms underpinning different ageing groups and elucidating appropriate probiotic strains for optimal gains in muscle mass and strength are warranted.

Abstract

Probiotics have been widely used in gastroenteritis due to acute and chronic illnesses. However, evidence supporting the effectiveness of probiotics in different health conditions is inconclusive and conflicting. The aim of this study was to review the existing literature on the effects of probiotics on gastroenteritis among adults. Only original articles on clinical trials that demonstrated the effects of probiotics in adults with gastroenteritis were used for this analysis. Multiple databases, such as PubMed, Google Scholar, MEDLINE and Scopus databases, were searched for the data. The study followed standard procedures for data extraction using a PRISMA flow chart. A quality appraisal of the selected studies was conducted using CADIMA. Finally, a meta-analysis was performed. Thirty-five articles met the selection criteria; of them, probiotics were found effective in the treatment and/or prevention of chronic inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease in 17 (49%), and the treatment of pouchitis in 4 (11.4%), antibiotic-induced diarrhea in 3 (8.6%), Helicobacter pylori infection in 2 (5.7%) and diverticulitis in 1 (2.9%), while the remaining 7 (20%) were ineffective, and 1 study's results were inconclusive. The meta-analysis did not demonstrate any significant protective effects of probiotics. Having a τ2 value of zero and I2 of 6%, the studies were homogeneous and had minimum variances. Further studies are suggested to evaluate the beneficial effects of probiotics in IBDs and other chronic bowel diseases.

Abstract

BACKGROUND Many preclinical studies have demonstrated the effectiveness of genetically modified probiotics (gm probiotics) in animal models of inflammatory bowel disease (IBD). OBJECTIVE This systematic review was performed to investigate the role of gm probiotics in treating IBD and to clarify the involved mechanisms. METHODS PubMed, Web of Science, Cochrane Library, and Medline were searched from their inception to 18 September 2022 to identify preclinical and clinical studies exploring the efficacy of gm probiotics in IBD animal models or IBD patients. Two independent researchers extracted data from the included studies, and the data were pooled by the type of study; that is, preclinical or clinical. RESULTS Forty-five preclinical studies were included. In these studies, sodium dextran sulfate and trinitrobenzene sulfonic acid were used to induce colitis. Eleven probiotic species have been genetically modified to produce therapeutic substances, including IL-10, antimicrobial peptides, antioxidant enzymes, and short-chain fatty acids, with potential therapeutic properties against colitis. The results showed generally positive effects of gm probiotics in reducing disease activity and ameliorating intestinal damage in IBD models; however, the efficacy of gm probiotics compared to that of wild-type probiotics in many studies was unclear. The main mechanisms identified include modulation of the diversity and composition of the gut microbiota, production of regulatory metabolites by beneficial bacteria, reduction of the pro- to anti-inflammatory cytokine ratio in colonic tissue and plasma, modulation of oxidative stress activity in the colon, and improvement of intestinal barrier integrity. Moreover, only one clinical trial with 10 patients with Crohn's disease was included, which showed that L. lactis producing IL-10 was safe, and a decrease in disease activity was observed in these patients. CONCLUSIONS Gm probiotics have a certain efficacy in colitis models through several mechanisms. However, given the scarcity of clinical trials, it is important for researchers to pay more attention to gm probiotics that are more effective and safer than wild-type probiotics to facilitate further clinical translation.

Abstract

During the disease course, most Inflammatory Bowel Disease patients present a condition of malnutrition, undernutrition, or even overnutrition. These conditions are mainly due to suboptimal nutritional intake, alterations in nutrient requirements and metabolism, malabsorption, and excessive gastrointestinal losses. A suboptimal nutritional status and low micronutrient serum levels can have a negative impact on both induction and maintenance of remission and on the quality of life of Inflammatory Bowel Disease patients. We performed a systematic review including all the studies evaluating the connection between nutrition, nutrition status (including undernutrition and overnutrition), micronutrient deficiency, and both disease course and therapeutic response in Inflammatory Bowel Disease patients. This systematic review was performed using PubMed/MEDLINE and Scopus. Four main clinical settings concerning the effect of nutrition on disease course in adult Inflammatory Bowel Disease patients were analyzed (induction of remission, maintenance of remission, risk of surgery, post-operative recurrence, and surgery-related complications). Four authors independently reviewed abstracts and manuscripts for eligibility. 6077 articles were found; 762 duplicated studies were removed. Out of 412 full texts analyzed, 227 were included in the review. The evidence summarized in this review showed that many nutritional aspects could be potential targets to induce a better control of symptoms, a deeper remission, and overall improve the quality of life of Inflammatory Bowel Disease patients.

Abstract

BACKGROUND High doses of oral thiamine improve clinical fatigue scores in patients with quiescent inflammatory bowel disease (IBD) and chronic fatigue. In this study we analysed plasma samples obtained in a randomised clinical trial and aimed compare levels of vitamins B1, B2, B3 and B6, and their related vitamers and metabolites in patients with IBD, with or without chronic fatigue and with or without effect of high dose oral thiamine for chronic fatigue. METHODS Blood samples from patients with fatigue were drawn prior and after thiamine exposure and only once for patients without fatigue. A wide panel of analysis were done at Bevital AS Lab. RESULTS Concentration of flavin mononucleotide (FMN) was lower in patients with chronic fatigue compared to patients without fatigue (p = 0.02). Patients with chronic fatigue who reported a positive effect on fatigue after 4 weeks of high dose thiamine treatment had a statistically significantly lower level of riboflavin after thiamine treatment (p = 0.01). CONCLUSION FMN and Riboflavin were associated with chronic fatigue in patients with quiescent IBD. Levels of other B vitamins and metabolites were not significantly different between the investigated groups or related to effect of the thiamine intervention. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov study identifier NCT036347359. Registered 15 August 2018, https://clinicaltrials.gov/study/NCT03634735?cond=Inflammatory%20Bowel%20Diseases&intr=Thiamine&rank=1.

Abstract

Over the past decade, the role of the gut microbiota in many disease states has gained a great deal of attention. Mounting evidence from case-control and observational studies has linked changes in the gut microbiota to the pathophysiology of osteoporosis (OP). Nonetheless, the results of these studies contain discrepancies, leaving the literature without a consensus on osteoporosis-associated microbial signatures. Here, we conducted a comprehensive meta-analysis combining and reexamining five publicly available 16S rRNA partial sequence data sets to identify gut bacteria consistently associated with osteoporosis across different cohorts. After adjusting for the batch effect associated with technical variation and heterogeneity of studies, we observed a significant shift in the microbiota composition in the osteoporosis group. An increase in the relative abundance of opportunistic pathogens Clostridium sensu stricto, Bacteroides, and Intestinibacter was observed in the OP group. Moreover, short-chain-fatty-acid (SCFA) producers, including members of the genera Collinsella, Megasphaera, Agathobaculum, Mediterraneibacter, Clostridium XIV, and Dorea, were depleted in the OP group relative to the healthy control (HC) group. Lactic acid-producing bacteria, including Limosilactobacillus, were significantly increased in the OP group. The random forest algorithm further confirmed that these bacteria differentiate the two groups. Furthermore, functional prediction revealed depletion of the SCFA biosynthesis pathway (glycolysis, tricarboxylic acid [TCA] cycle, and Wood-Ljungdahl pathway) and amino acid biosynthesis pathway (methionine, histidine, and arginine) in the OP group relative to the HC group. This study uncovered OP-associated compositional and functional microbial alterations, providing robust insight into OP pathogenesis and aiding the possible development of a therapeutic intervention to manage the disease. IMPORTANCE Osteoporosis is the most common metabolic bone disease associated with aging. Mounting evidence has linked changes in the gut microbiota to the pathophysiology of osteoporosis. However, which microbes are associated with dysbiosis and their impact on bone density and inflammation remain largely unknown due to inconsistent results in the literature. Here, we present a meta-analysis with a standard workflow, robust statistical approaches, and machine learning algorithms to identify notable microbial compositional changes influencing osteoporosis.

Abstract

Exposure to early life stress (ELS), prenatal or postnatal during childhood and adolescence, can significantly impact mental and physical health. The role of the intestinal microbiome in human health, and particularly mental health, is becoming increasingly evident. This systematic review aims to summarize the clinical data evaluating the effect of ELS on the human intestinal microbiome. The systematic review (CRD42022351092) was performed following PRISMA guidelines, with ELS considered as exposure to psychological stressors prenatally and during early life (childhood and adolescence). Thirteen articles met all inclusion criteria, and all studies reviewed found a link between ELS and the gut microbiome in both prenatal and postnatal periods. However, we failed to find consensus microbiome signatures associated with pre- or postnatal stress, or both. The inconsistency of results is likely attributed to various factors such as different experimental designs, ages examined, questionnaires, timing of sample collection and analysis methods, small population sizes, and the type of stressors. Additional studies using similar stressors and validated stress measures, as well as higher-resolution microbiome analytical approaches, are needed to draw definitive conclusions about the links between stress and the human gut microbiome.

Abstract

Observational studies suggest a link between vitamin D and the composition of the gut microbiome, but there is little evidence from randomized controlled trials of vitamin D supplementation. We analyzed data from the D-Health Trial, a randomized, double-blind, placebo-controlled trial. We recruited 21,315 Australians aged 60-84 y and randomized them to 60,000 IU of vitamin D3 or placebo monthly for 5 y. Stool samples were collected from a sample of 835 participants (417 in the placebo and 418 in the vitamin D group) approximately 5 y after randomization. We characterized the gut microbiome using 16S rRNA gene sequencing. We used linear regression to compare alpha diversity indices (i.e. Shannon index (primary outcome), richness, inverse Simpson index), and the ratio of Firmicutes to Bacteroidetes between the two groups. We analyzed between-sample (beta) diversity (i.e. Bray Curtis distance and UniFrac index) using principal coordinate analysis and used PERMANOVA to test for significant clustering according to randomization group. We also assessed the difference in the abundance of the 20 most abundant genera between the two groups using negative binomial regression model with adjustment for multiple testing. Approximately half the participants included in this analysis were women (mean age 69.4 y). Vitamin D supplementation did not alter the Shannon diversity index (mean 3.51 versus 3.52 in the placebo and vitamin D groups, respectively, p = 0.50). Similarly, there was little difference between the groups for other alpha diversity indices, the abundance of different genera, and the Firmicutes-to-Bacteroidetes ratio. We did not observe clustering of bacterial communities according to randomization group. In conlusion, monthly doses of 60,000 IU of vitamin D supplementation for 5 y did not alter the composition of the gut microbiome in older Australians.