Tomomi Komura

In Parkinson's disease (PD), α–synuclein (αSyn) accumulation drives neuropathological progression, establishing it as a potential therapeutic target. Lactic acid bacteria (LAB) provide various health benefits to the host and are expected to offer protective effects on neurological functions through the brain–gut connection, as indicated by animal studies. However, the protective effects of LAB against αSyn are not well understood. We investigated whether LAB feeding could reduce αSyn accumulation and improve mobility in transgenicCaenorhabditis elegans, an invertebrate model organism that expresses human αSyn in muscle. Among the nine screened strains,Pediococcus pentosaceussuppressed αSyn accumulation and the decrease in bending counts, a locomotion index in nematodes. Additionally, feedingP. pentosaceustoOryzias latipes(medaka), a vertebrate model organism, alleviated PD–like behavioral defects induced by 1–methyl–4–phenyl–1,2,3,6–tetrahydropyridine.P. pentosaseusacts as a probiotic against PD, and PD model worms and medaka can be used to screen effective LAB for prevention.

Several approaches for regulating health and disease by intestinal bacteria, bacteria isolated from food products, and food factors have been investigated; however, the molecular mechanisms underlying the interactions between these bacteria and their hosts are still unknown. Caenorhabditis elegans is a crucial model for exploring various biological phenomena and has been used in studying intestinal bacteria, mainly in the field of antiaging, anti-amyloid β activity in Alzheimer's disease, and its interaction to hosts. The nematode model is expected to be increasingly utilized for elucidating the interactions of beneficial bacteria or food factors with hosts. Herein, we review anti-aging and suppression of amyloid-β expression in a C. elegans model fed lactic acid bacteria, and our developed methods for orally administering food factors and assessing advanced glycation end products as an aging indicator.

Abstract Lactic acid bacteria (LAB) contribute to human health, and LAB functionality has been studied using Caenorhabditis elegans as an alternative host. However, many studies have focused on the efficacy of a single strain of LAB, and few reports have compared various LAB strains. In this study, we examined the effects of 15 strains of LAB isolated from vegetables, meat, and fermented foods on nematode longevity and healthy lifespan. To reduce the frequency of laborious survival observations, we performed a lifespan assay on agar plates containing 2′-deoxy-5-fluorouridine (FUdR), which inhibits egg-hatching and prevents generation mixing. Four beneficial strains showed significant lifespan extension and increased spontaneous nematode mobility, regardless of treatment with or without FUdR and the frequency of survival observation. These results suggested increased longevity and an extended healthy lifespan, which confirming the reliability of our method. The four strains are expected to show anti-ageing effects besides longevity and have effects on age-related degenerative diseases. Our labour-saving method can be used as an alternative to conventional methods and enable simultaneous screening of multiple strains. Future research could explore factors contributing to lifespan regulation by comparing and verifying differential strain effects on lifespan.