TNF and osteoporosis: Moreover, there was obvious gut barrier damage in the osteoporotic mice, with decreased expression of SIgA, increased expression of LPS, IL-6, IL-1β, and TNF-α in intestinal tissues, as well as increased serum levels of LPS, suggesting that the intestinal microenvironment of the mice was disturbed in the osteoporosis mouse model, leading to damage of the gut barrier.