Desh D. Singh

Probiotic therapy: immunomodulating approach toward urinary tract infection.

Urinary tract infection (UTI) is an extremely common health problem, with an unpredictable history. Members of enterobacteriaceae family such as Escherichia coli, which are normal inhabitants of human intestines, account for the majority of these uncomplicated infections. Rarely, UTI can result from virus or fungus. There is a close correlation between loss of the normal genital microbiota, particularly Lactobacillus species, and an increased incidence of genital and bladder infections. Although antimicrobial agents are generally effective in eradicating these infections, there is a high incidence of recurrence. Use of Lactobacillus species to combat UTI is now giving modern concept of modern genitourinary vaccine with the facts that it not only maintains low pH of the genital area, produces hydrogen peroxide and hinders the growth of E. coli but also activates Toll-like receptor-2 (TLR2), which produces interleukin-10 (IL-10) and myeloid differentiation factor 88 (MyD88). E. coli activates TLR4, which is responsible for the activation of IL-12, extracellular signal–regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). This process downregulates inflammatory reactions caused due to pathogens. Current review covers the probiotics-based TLR therapy and shed some knowledge for the use of Lactobacillus species as probiotics.

Innate and specific gut-associated immunity and microbial interference.

Certain bacterial species isolated from the gastrointestinal microbial communities release low-molecular-weight peptides into milk products using bacteria-derived proteases that degrade milk casein, and thereby generate peptides, triggering immune responses. The intestinal microbial communities contributes to the processing of food antigens in the gut. The present study was designed to investigate the immunomodulatory effects of microbial interference to determine whether casein degraded by probiotic bacteria-derived enzymes could modulate the cytokine production and peripheral blood mononuclear cells in atopic infants with cow or other synthetic milk allergy. Without hydrolyzation, casein reduced the production of interleukin-4, which indicates that probiotics modify the structure of potentially harmful antigens and thereby alter the mode of their immunogenicity. Intraluminal bacterial antigens have been reported to elicit specific responses in the gut-associated lymphoid tissue (GALT) through the binding capacity of intraluminal bacterial antigens to epithelial cells, which allows antigen entry via enterocytes and aids in evading the tolerance function in Peyers patches. Such tonic immune responses in the GALT may allow control of the metabolic activity and balance of the gut microbial communities.