Gut enterotypes are stable during Bifidobacterium and Lactobacillus probiotic supplementation

Enterotype-Dependent Probiotic-Mediated Changes in the Male Rat Intestinal Microbiome In Vivo and In Vitro

Beneficial properties of lactic acid bacteria have been known long ago, but particular interest in probiotics has arisen in the last two decades due to the understanding of the important role of intestinal microflora in human life. Thus, the ability of probiotics to support healthy homeostasis of gut microbiomes has received particular attention. Here, we evaluated the effect of a probiotic consisting of Bifidobacterium longum and Lacticaseibacillus paracasei on the gut microbiome of male rats, assessed their persistence in the fecal biota, and compared probiotic-mediated changes in vitro and in vivo. As expected, microbiomes of two enterotypes were identified in the feces of 21 animals, and it turned out that even a single dose of the probiotic altered the microbial composition. Upon repeated administration, the E1 biota temporarily acquired properties of the E2 type. Being highly sensitive to the intervention of probiotic bacteria at the phylum and genus levels, the fecal microbiomes retained the identity of their enterotypes when transferred to a medium optimized for gut bacteria. For the E2 biota, even similarities between probiotic-mediated reactions in vitro and in vivo were detected. Therefore, fecal-derived microbial communities are proposed as model consortia to optimize the response of resident bacteria to various agents.

Distinct Gut Microbial Enterotypes and Functional Dynamics in Wild Striped Field Mice (Apodemus agrarius) across Diverse Populations

Rodents, including the striped field mouse (Apodemus agrarius), play vital roles in ecosystem functioning, with their gut microbiota contributing significantly to various ecological processes. Here, we investigated the structure and function of 94 wild A. agrarius individuals from 7 geographic populations (45°57' N, 126°48' E; 45°87' N, 126°37' E; 45°50' N, 125°31' E; 45°59' N, 124°37' E; 46°01' N, 124°88' E; 46°01' N, 124°88' E; 46°01' N, 124°88' E), revealing two distinct enterotypes (Type1 and Type2) for the first time. Each enterotype showed unique microbial diversity, functions, and assembly processes. Firmicutes and Bacteroidetes dominated, with a significant presence of Lactobacillus and Muribaculaceae. Functional analysis highlighted metabolic differences, with Type1 emphasizing nutrient processing and Type2 showing higher energy production capacity. The analysis of the neutral model and the null model revealed a mix of stochastic (drift and homogenizing dispersal) and deterministic processes (homogenous selection) that shape the assembly of the microbiota, with subtle differences in the assembly processes between the two enterotypes. Correlation analysis showed that elevation and BMI were associated with the phylogenetic turnover of microbial communities, suggesting that variations in these factors may influence the composition and diversity of the gut microbiota in A. agrarius. Our study sheds light on gut microbial dynamics in wild A. agrarius populations, highlighting the importance of considering ecological and physiological factors in understanding host-microbiota interactions.

Structure-dependent stimulation of gut bacteria by arabinoxylo-oligosaccharides (AXOS): a review

Arabinoxylo-oligosaccharides (AXOS) are non-digestible dietary fibers that potentially confer a health benefit by stimulating beneficial bacteria in the gut. Still, a detailed overview of the diversity of gut bacteria and their specificity to utilize structurally different AXOS has not been provided to date and was aimed for in this study. Moreover, we assessed the genetic information of summarized bacteria, and we extracted genes expected to encode for enzymes that are involved in AXOS hydrolysis (based on the CAZy database). The taxa involved in AXOS fermentation in the gut display a large variety of AXOS-active enzymes in their genome and consequently utilize AXOS to a highly different extent. Clostridia and Bacteroidales are generalists that consume many structurally diverse AXOS, whereas Bifidobacterium are specialists that specifically consume AXOS with a low degree of polymerization. Further complexity is evident from the fact that the exact bacterial species, and in some cases even the bacterial strains (e.g. in Bifidobacterium longum) that are stimulated, highly depend on the specific AXOS molecular structure. Furthermore, certain species in Bifidobacterium and Lactobacillaceae are active as cross-feeders and consume monosaccharides and unbranched short xylo-oligosaccharides released from AXOS. Our review highlights the possibility that (enzymatic) fine-tuning of specific AXOS structures leads to improved precision in targeting growth of specific beneficial bacterial species and strains in the gut.

Understanding the "individual drug reaction" from the perspective of the interaction between probiotics and lovastatin in vitro and in vivo

BACKGROUND

The existence of the gut microbiota produces an "individual drug reaction." As members of the intestinal microbiota, probiotics, although they have prebiotic functions, may accelerate the degradation of drugs, thereby affecting drug efficacy. Lovastatin is one of the well-recognized lipid-lowering drugs. Its main action site is the liver. Therefore, if it is degraded in advance by gastrointestinal probiotics, its efficacy may be reduced.

RESULTS

Here, we designed a two-stage experiment in vitro and in vivo to explore the degradation of lovastatin by probiotics. In vitro, the degradation of lovastatin by 83 strains of Lactiplantibacillus plantarum and the "star strain" Lacticaseibacillus paracasei strain Shirota was investigated by high-performance liquid chromatography (HPLC). The results showed that probiotics could degrade lovastatin to varying degrees. Subsequently, we selected Lactiplantibacillus plantarum A5 (16.87%) with the strongest ability to degrade lovastatin, Lactiplantibacillus plantarum C3 (4.61%) with the weakest ability to degrade lovastatin and Lacticaseibacillus paracasei strain Shirota (17.6%) as representative probiotics for in vivo experiments. In vivo, the therapeutic effect of lovastatin combined with probiotics on golden hamsters with mixed hyperlipidemia was evaluated by measuring blood indicators, intestinal microbiota metagenomic sequencing, and the liver transcriptome. The results showed that the intake of probiotics did not affect the efficacy of lovastatin and could slow the inflammatory reaction of the liver.

CONCLUSIONS

The supplementation of probiotics produced beneficial metabolites in the intestine by promoting beneficial microbes. Intestinal metabolites affected the expression of the liver genes through the gut-liver axis, increased the relative content of the essential amino acids, and finally improved the liver inflammatory response of the host. This study aims to reveal the impact of probiotics on the human body from a unique perspective, suggesting the impact of taking probiotics while taking drugs. Video Abstract.

Isomaltooligosaccharides Sustain the Growth of Prevotella Both In Vitro and in Animal Models

The human digestive tract is colonized by trillions of bacterial cells that play important roles in human health and diseases. It is well known that dietary habits are associated with human microbiota enterotypes. However, the factors that determine the enterotype still remain elusive. In this study, it was first examined, via in vitro batch fermentation, how different carbohydrates affect the Bacteroides and Prevotella enterotypes. Among the 11 substrates (fructo-, galacto-, xylo-, manno-, and isomalto-oligosaccharides [IMO] and lactulose, raffinose, starch, inulin [INU], mannitol, and xylitol) tested, IMO, INU, and starch were found to sustain the growth of Prevotella through batch fermentation. The development of the Prevotella and Bacteroides enterotypes was further simulated in chemostats using fecal samples. IMO coupled with faster dilution rates and lower pH were required to sustain the growth of Prevotella copri in the chemostat based on 16S rRNA gene and metagenomic sequencing. Meanwhile, starch with relatively lower dilution rates and higher pH was required to support the development of the Bacteroides enterotype. Amylo-α-1,6-glucosidase, pectin, and xylan lyases were the carbohydrate-active enzymes associated with the Prevotella enterotype. The Bacteroides enterotype was associated with more diversified carbohydrate-active enzymes. Consistently, since honey contains high isomaltose content, mice fed IMO and honey displayed an increased relative abundance of Prevotella in the colon. In conclusion, both in vitro systems and a mouse model were used to demonstrate that IMO maintains the Prevotella enterotype. This result provides insight into the nutritional requirements underlying gut enterotype formation. IMPORTANCE The Prevotella enterotype type is a human traditional enterotype with high dietary fiber intake, which is related to healthy ageing and Parkinson's disease development. Manipulations of the dwelled gut microbes by dietary isomalto-oligosaccharides efficiently sustained Prevotella type enterotypes, indicating that it can be used in the improvement of elderly health by increasing the gut transit time.

Minimal Influence of Cayenne Pepper on the Human Gastrointestinal Microbiota and Intestinal Inflammation in Healthy Adult Humans-A Pilot Study

Diet impacts human gut microbial composition. Phytochemicals in cayenne pepper (CP), such as capsaicin, have anti-inflammatory properties and alter bacterial growth in vitro. However, the evidence that CP impacts the human microbiota and intestinal inflammation in free-living adults is lacking. Thus, the objective of this randomized cross-over study was to determine the influence of CP on human gut microbiota and intestinal inflammation in vivo. A total of 29 participants were randomly allocated to consume two 250 mL servings of tomato juice plus 1.8 g of CP each day or juice only for 5 days before crossing over to the other study arm. Fecal samples were analyzed. CP reduced Oscillibacter and Phascolarctobacterium but enriched Bifidobacterium and Gp6. When stratified by BMI (body mass index), only the increase in Gp6 was observed in all BMI groups during CP treatment. Stool concentrations of lipocalin-2 and calprotectin were similar regardless of CP treatment. However, lipocalin-2 and calprotectin levels were positively correlated in samples taken after CP consumption. Neither lipocalin-2 nor calprotectin levels were related to gut microbial composition. In conclusion, in healthy adult humans under typical living conditions, consumption of CP minimally influenced the gut microbiota and had little impact on intestinal inflammation.

The Cutting Edge of Gastroenteritis: Advances in Understanding of Enteric Infection

ABSTRACT

In recent years, multiple advances have been made in the care, diagnosis, and mechanistic understanding of acute gastroenteritis (AGE). In this review, we discuss the current state of the art of diagnosis and management, as well as how changes in practice can improve care and decrease costs. We will discuss present study demonstrating the effect of AGE on the microbiome and how that may be linked to secondary effects or long-term changes. We will explore the use of novel technologies to further our capacity to understand how gastrointestinal infections occur and promulgate. Finally, will discuss advances in our understanding of how gastrointestinal infections capacitate other changes such as post-viral motility or other post viral intestinal dysfunction.

Effectiveness of Multistrain Probiotic Formulation on Common Infectious Disease Symptoms and Gut Microbiota Modulation in Flu-Vaccinated Healthy Elderly Subjects

The decline of the immune system with aging leads elderly people to be more susceptible to infections, posing high risk for their health. Vaccination is thus important to cope with this risk, even though not always effective. As a strategy to improve protection, adjuvants are used in concomitance with vaccines, however, occasionally producing important side effects. The use of probiotics has been proposed as an alternative to adjuvants due to their efficacy in reducing the risk of common infections through the interactions with the immune system and the gut microbiota. A placebo-controlled, randomized, double-blind, clinical trial was carried out on fifty elderly subjects, vaccinated for influenza, to determine the efficacy of a probiotic mixture in reducing common infection symptoms. The incidence of symptoms was evaluated after 28 days of probiotic intake (namely, T28) and after further 28 days of follow-up (namely, T56). The number of subjects, as well as the number of days with symptoms, was remarkably reduced at T28, and even more at T56 in the probiotic group. Furthermore, the influence of probiotics on immunological parameters was investigated, showing a significant positive improvement of total antioxidant capacity and β-defensin2 levels. Finally, faecal samples collected from participants were used to assess variations in the gut microbiota composition during the study, showing that probiotic intake enhanced the presence of genera related to a healthy status. Therefore, the collected results suggested that the treatment with the selected probiotic mixture could help in reducing common infectious disease symptom incidence through the stimulation of the immune system, improving vaccine efficacy, and modulating the composition of the resident gut microbiota by enhancing beneficial genera.

Effect of the administration of probiotics on the fecal microbiota of adult individuals

Probiotics have been used to ameliorate ailments by modulating gut microbiota. However, to date, the effects of probiotic supplementation on the composition of fecal microbiota in healthy adults remain obscure. In this study, nine healthy volunteers were recruited to take probiotics (a mixture of Lactobacillus casei Zhang, L. plantarum P-8, and Bifidobacterium lactis V9, 2:2:3, 1 × 1010 CFU/day) for 28 days. The fecal samples were collected at 0 and 28 days, and V4 of the 16S rRNA gene sequenced by Illumina MiSeq was used to analyze the fecal microbiota. The enterotype has been used to characterize the composition of gut microbiota. Nine adults were divided into Type P (fecal microbiota dominated by Prevotella, 4 adults) and Type B (fecal microbiota dominated by Bacteroides, 5 adults) based on an enterotype analysis. The responses of variation had been found in two enterotypes. The α-diversity was not changed significantly after the administration of probiotics in both Type P and B. However, the community structure in Type B was substantially influenced. After the administration of probiotics, Weissella and Leuconostoc were significantly higher in Type P, while Collinsella significantly increased in Type B. The different pathways involving pathogen infections were downregulated at 28 days. The Type VI secretion system and the EHEC/EPEC pathogenicity signature were downregulated in Type B and Type P, respectively.

An Intervention With Michigan-Grown Wheat in Healthy Adult Humans to Determine Effect on Gut Microbiota: Protocol for a Crossover Trial

BACKGROUND

Daily fiber intake can increase the diversity of the human gut microbiota as well as the abundance of beneficial microbes and their metabolites. Whole-grain wheat is high in fiber.

OBJECTIVE

This manuscript presents a study protocol designed to understand the effects of different types of wheat on gastrointestinal tract microbes.

METHODS

Human adults will consume crackers made from three types of wheat flour (refined soft white wheat, whole-grain soft white wheat, and whole-grain soft red wheat). In this study, participants will alternate between crackers made from refined soft white wheat flour to those made from whole-grain soft white wheat and whole-grain soft red wheat flour. Survey and stool sample collection will occur after 7-day treatment periods. We will assess how wheat consumption affects gastrointestinal bacteria by sequencing the V4 region of 16S rRNA gene amplicons and the inflammatory state of participants' intestines using enzyme-linked immunosorbent assays. The butyrate production capacity of the gut microbiota will be determined by targeted quantitative real-time polymerase chain reaction.

RESULTS

We will report the treatment effects on alpha and beta diversity of the microbiota and taxa-specific differences. Microbiota results will be analyzed using the vegan package in R. Butyrate production capacity and biomarkers of intestinal inflammation will be analyzed using parametric statistical methods such as analysis of variance or linear regression. We expect whole wheat intake to increase butyrate production capacity, bacterial alpha diversity, and abundance of bacterial taxa responsive to phenolic compounds. Soft red wheat is also expected to decrease the concentration of inflammatory biomarkers in the stool of participants.

CONCLUSIONS

This protocol describes the methods to be used in a study on the impact of wheat types on the human gastrointestinal microbiota and biomarkers of intestinal inflammation. The analysis of intestinal responses to the consumption of two types of whole wheat will expand our understanding of how specific foods affect health-associated outcomes.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/29046.

Restraint Stress in Hypertensive Rats Activates the Intestinal Macrophages and Reduces Intestinal Barrier Accompanied by Intestinal Flora Dysbiosis

Purpose

Hypertension (HTN) is a major risk factor for cardiovascular disease. In recent years, there were numerous studies on the function of stress in HTN. However, the gut dysbiosis linked to hypertension in animal models under stress is still incompletely understood. Purpose of this study is to use multiple determination method to determine the juvenile stage intestinal bacteria, cytokines and changes in hormone levels.

Methods

Four groups of juvenile male spontaneously hypertensive rats (SHRs) and age-matched male Wistar-Kyoto (WKY) rats were randomly selected as control and experimental groups. Rats in the two stress groups were exposed to restraint stress for 3 hours per day for 7 consecutive days. In one day three times in the method of non-invasive type tail-cuff monitoring blood pressure. The detailed mechanism was illuminated based on the intestinal change using immunohistochemical and immunofluorescence staining and the stress-related hormone and inflammation factors were analyzed via ELISA method. The integrity of the epithelial barrier was assessed using FITC/HRP and the expression levels of proteins associated with the tight junction was detected by Western blot. The alteration of stress-related intestinal flora from ileocecal junction and distal colon were also analyzed using its 16S rDNA sequencing.

Results

The results indicate that acute stress rapidly increases mean arterial pressure which is positive correlation to hormone concentration, especially in SHR-stress group. Meanwhile, stress promoted the enhancement of epithelial permeability accompanied with a reduced expression of the tight junction-related protein and the macrophages (Mφ) aggregation to the lamina propria. There were remarkable significant increase of stress-related hormones and pro-inflammatory factor interleukin (IL)-6 along with a decrease in the diversity of intestinal flora and an imbalance in the F/B ratio.

Conclusion

Our results reveal that stress accompanied with HTN could significantly disrupt the domino effect between intestinal flora and homeostasis.