Bifidobacterium bifidum CCFM1359 alleviates intestinal motility disorders through the BDNF-TrkB pathway

Intestinal motility disorder is characterised by abnormal intestinal motility function, often resulting in symptoms such as diarrhoea and constipation. Probiotics are increasingly recognised as an effective treatment for gastrointestinal disorders, including intestinal motility disorders. In this study, we used senna extract to induce an animal model of intestinal dysfunction characterised by BDNF downregulation. By assessing relevant indicators of intestinal dyskinesia, we found that Bifidobacterium bifidum CCFM1359 effectively alleviated the dyskinesia. However, this alleviating effect was nullified when a TrkB receptor inhibitor was introduced, suggesting that Bifidobacterium bifidum CCFM1359 operates through the BDNF-TrkB pathway. Further analysis revealed that Bifidobacterium bifidum CCFM1359 likely exerts its beneficial effects by regulating intestinal microecology (increasing the relative abundance of Bifidobacterium bifidum and valeric acid content while decreasing Faecalibacterium and butyric acid content), reducing intestinal inflammation (upregulating the anti-inflammatory factor IL-10 and downregulating pro-inflammatory factors TNF-α and IL-1β), and remodelling intestinal nerves (upregulating S100β and the excitatory neurotransmitter ACh, while downregulating the inhibitory neurotransmitter nNOS). This study provides a theoretical basis for using probiotics to alleviate intestinal motility disorders.