Comparative study of probiotic effects of Lactobacillus and Bifidobacteria strains on cholesterol levels, liver morphology and the gut microbiota in obese mice

Gut Microbiota and Fecal Metabolome Perturbation in Children with Autism Spectrum Disorder

The brain-intestinal axis concept describes the communication between the intestinal microbiota as an ecosystem of a number of dynamic microorganisms and the brain. The composition of the microbial community of the human gut is important for human health by influencing the total metabolomic profile. In children with autism spectrum disorder (ASD), the composition of the fecal microbiota and their metabolic products has a different configuration of the healthy child. An imbalance in the metabolite derived from the microbiota in children with ASD affect brain development and social behavior. In this article, we review recent discoveries about intestinal metabolites derived from microbiota based on high-yield molecular studies in children with ASD as part of the "intestinal brain axis"

Specific properties of probiotic strains: relevance and benefits for the host

BACKGROUND

Probiotics have tremendous potential to develop healthy diets, treatment, and prevention. Investigation of in vitro cultural properties of health-promoting microorganisms like lactic acid bacteria (LAB) and bifidobacteria is crucial to select probiotic strains for treatments based on gut microbiota modulation to justify individualized and personalized approach for nutrition and prevention of variety of diseases. The aim was to study the biological properties of LAB and bifidobacteria probiotic strains, namely adhesive properties; resistance to antibiotics; and biological fluids (gastric juice, bile, pancreatic enzymes), and to overview the literature in the field.

MATERIALS AND METHODS

We studied six LAB strains (Lactobacillus acidophilus ІМV В-7279, L. casei ІМV В-7280, L. delbrueckii subsp. bulgaricus ІМV В-7281, L. rhamnosus LB-3 VK6, L. delbrueckii LE VK8, L. plantarum LM VK7), and two bifidobacteria strains (Bifidobacterium animalis VKL, B. animalis VKB). We characterized tinctorial, culturally morphological, physiological, and biochemical properties of probiotic strains of LAB and bifidobacteria by commonly used research methods. Determination of the resistance to antibiotics was carried out using disc-diffusion method. The effects of gastric juice, bile, and pancreatin on the viability of LAB and bifidobacteria were evaluated. Adhesive properties of LAB and bifidobacteria to epithelial cells were assessed calculating three indicators: average adhesion rate (AAR), participation rate of epithelial cells (PRE), and adhesiveness index of microorganisms (AIM). Electron microscopy of LAB and bifidobacteria cells was conducted.

RESULTS

The studied strains of LAB and bifidobacteria did not form spores, were positively stained by Gram, grow on medium in a wide range of pH (1.0-9.0, optimum pH 5.5-6.5), were sensitive to a wide range of antibiotics; and showed different resistance to gastric juice, bile, and pancreatic enzymes. The most resistant to antibiotics were L. rhamnosus LB-3 VK6 and L. delbrueckii LE VK8 strains. The most susceptible to gastric juice was L. plantarum LM VK7, which stopped its growth at 8% of gastric juice; L. acidophilus IMV B-7279, B. animalis VKL, and B. animalis VKB strains were resistant even in the 100% concentration. Strains L. acidophilus IMV В-7279, L. casei IMV В-7280, B. animalis VKL, B. animalis VKB, L. rhamnosus LB-3 VK6, L. delbrueckii LE VK8, and L. delbrueckii subsp. bulgaricus IMV В-7281 were resistant to pancreatic enzymes. Adhesive properties of the strains according to AIM index were high in L. casei IMV В-7280, B. animalis VKL, and B. animalis VKB; were moderate in L. delbrueckii subsp. bulgaricus IMV В-7281; and were low in L. acidophilus IMV В-7279, L. rhamnosus LB-3 VK6, L. delbrueckii LE VK8, and L. plantarum LM VK7.

CONCLUSION

We recognized strain-dependent properties of studied LAB and bifidobacteria probiotic strains (adhesive ability, resistance to antibiotics, and gut biological fluids) and discussed potential for most effective individualized treatment for gut and distant sites microbiome modulation.

Probiotic Species in the Modulation of Gut Microbiota: An Overview

Probiotics are microbial strains that are beneficial to health, and their potential has recently led to a significant increase in research interest in their use to modulate the gut microbiota. The animal gut is a complex ecosystem of host cells, microbiota, and available nutrients, and the microbiota prevents several degenerative diseases in humans and animals via immunomodulation. The gut microbiota and its influence on human nutrition, metabolism, physiology, and immunity are addressed, and several probiotic species and strains are discussed to improve the understanding of modulation of gut microbiota. This paper provides a broad review of several Lactobacillus spp., Bifidobacterium spp., and other coliform bacteria as the most promising probiotic species and their role in the prevention of degenerative diseases, such as obesity, diabetes, cancer, cardiovascular diseases, malignancy, liver disease, and inflammatory bowel disease. This review also discusses a recent study of Saccharomyces spp. in which inflammation was prevented by promotion of proinflammatory immune function via the production of short-chain fatty acids. A summary of gut microbiota alteration with future perspectives is also provided.