Modification of Ganoderma lucidum spore shells into probiotic carriers: selective loading and colonic delivery of Lacticaseibacillus rhamnosus and effective therapy of inflammatory bowel disease†

Inflammatory bowel disease (IBD) is a chronic inflammation with a high incidence rate. Many probiotics, including Lacticaseibacillus rhamnosus (L. rhamnosus), have shown promise in IBD treatment. The therapeutic effects of most probiotics are greatly decided by the available live cells in the disease lesion, which is compromised as they pass through the gastric juice and intestinal tract, resulting in a loss of activity. To improve probiotic delivery efficiency in the intestinal tract, broken Ganoderma lucidum spore shells (bGLS) were explored as a carrier to enhance the intestinal tract delivery of L. rhamnosus SHA113, a probiotic that has been verified to have capability to treat IBD. It was found the bGLS treated with iturin A and hydrochloric acid (IH-bGLS) had much higher affinity to probiotic cells than the untreated ones. This is possibly due to the enhancement of hydrophobic and positive charge of bGLS. Furthermore, IH-bGLS demonstrated an 81% loading efficiency for L. rhamnosus SHA113 and 2.2% for Escherichia coli. More importantly, loading in IH-bGLS greatly enhanced the delivery of L. rhamnosus SHA113 cells to the colon and prolonged their retention time from 48 to over 120 h (P < 0.01). The mechanisms might be related to the enhancement of probiotic cell adhesion to the gastrointestinal mucosa, increase of mucus secretion and the upregulated expression of tight junction proteins, occludin and ZO-1, in the colon. The results of the animal experiment showed that the therapeutic effects of L. rhamnosus SHA113 on IBD were greatly enhanced when they were loaded with IH-bGLS. The novelty of this research is in the development of probiotic carriers from bGLS, which has significance in the improvement of intestinal delivery efficiency and the therapeutic effects of probiotics on IBD. This system may have attractive application in the enhancement of probiotic delivery efficiency in the intestinal tract, which is important to ensure and enhance the beneficial effects of probiotics.