Webberley et al. (2022) found that Lab4b probiotics were neuroprotective, increased mRNA expression of memory-related brain markers (including BDNF, CPLX2, and GRIA1), and reduced levels of the pro-inflammatory factor IL-10. The dietary combination of Lactobacillus probiotics and Bifidobacterium Bifidus seems to alleviate loss of brain weight in 3xTg-AD mice (Bonfili et al., 2017) and prevent cognitive decline in aging rats, AD mice, and people with AD (Akbari et al., 2016; Bonfili et al., 2017; O’Hagan et al., 2017). Here, BDNF is linked to Alzheimer disease.