Host microbial cross talk is essential to maintain intestinal homeostasis. However, maladaptation of the response through microbial dysbiosis or defective host defense toward invasive intestinal microbial results in chronic inflammation and the mild cognitive impairment. The role of active constituents from Aloe species, fermented butyrate, and micRNAs on Alzheimer’s disease, and Parkinson’s disease is discussed on the basis of gut microbiota-gut-brain axis. And prophylactic hyaluronan to knee osteoarthritis is discussed on the basis of functional relationship between osteogenesis and angiogenesis in tissue regeneration. Furthermore, two case reports suggest that the successive ingestion of aloe vera juice provides high concentration of the butyrogenic microbiome Faecalibacterium spp. in fecal, and could play a beneficial role for tissue repair and bone regeneration. CLICK TO REVIEW