Lactic Acid Bacteria Isolated from Human Feces of Vegetarian and Non-Vegetarians

Introduction

The human body co-exists with around 1000 diverse bacterial species that contribute to the maintenance of host homeostasis. The gastrointestinal tract (GIT) constitutes a significant distinct habitat for these microbes, primarily comprising beneficial biota such as lactic acid bacteria (LAB). Dysbiosis of the microbial community can lead to compromised gut function and increased illness susceptibility.¹ LAB represent a varied collection of microbes characterised by their production of lactic acid as the main by-product of carbohydrate metabolism. LAB are defined as Gram-positive, typically non-motile, non-sporogenic organisms that generate lactic acid as a primary or exclusive outcome of their fermentative processes. They are a collection of rod-shaped, lactic acid-producing, phylogenetically diverse organisms.² Lactobacilli are commonly found in various natural environments and are often present in fermented foods, including dairy products, beverages, fish, pork, and vegetables, as well as in sewage.³ Certain species are thought to be part of the commensal flora in the human GIT and are utilised as probiotics to combat diseases.⁴ The significance of LAB as a primary category of probiotics is recognised by the majority of researchers. Recently, a variety of studies have been conducted on the identification of probiotic microorganisms.⁵ A variety of bacterial and yeast genera are utilised as probiotics, such as Bifidobacterium, Leuconostoc, Pediococcus, Lactobacillus, and Enterococcus. However, the primary species recognised for their probiotic properties include Bifidobacterium spp., Lactobacillus casei, andLactobacillus acidophilus. These probiotics are defined as “living microorganisms that, when provided in sufficient quantities, offer a health advantage to the host”.⁶ Probiotics possess significant potential to positively impact the host by altering immune responses and affecting metabolic functions, such as cholesterol assimilation, lactase activity, and vitamin production.^7,8 In this study, the Lactobacillus species was isolated from the faeces of human beings having vegetarian and non-vegetarian diets. Vegetarian and vegan diets cultivate distinct microbiota in comparison to omnivorous diets, with only a slight variation observed between vegans and vegetarians.⁹ Alterations in microbiota composition may result from discrepancies in microorganisms ingested by food, variances in substrates eaten, and fluctuations in transit time through the gastrointestinal tract. A plant-based diet seems advantageous for human health by fostering a more diversified gut microbial ecosystem and...