Clostridium butyricum Alleviates Gut Microbiota Alteration-Induced Bone Loss after Bariatric Surgery by Promoting Bone Autophagy.

Bariatric surgery is the most common and effective treatment of severe obesity; however, these bariatric procedures always result in detrimental effects on bone metabolism by underlying mechanisms. This study aims to investigate the skeletal response to bariatric surgery and to explore whether Clostridium butyricum alleviates gut microbiota alteration-induced bone loss after bariatric surgery. Consequently, male SD rats received Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) surgery, respectively, followed by body weight recording. The bone loss after bariatric surgery was further determined by dual-energy X-ray absorptiometry (DXA), micro-CT measurement, histologic analyses, and Western blot. Besides, 16S rDNA gene sequencing was performed to determine the gut microbiota alteration after surgery, and intervention with fecal microbiota from RYGB donor was conducted in obese SD rats, followed by C. butyricum administration. Accordingly, rats in the RYGB and SG groups maintained sustained weight loss, and DXA and micro-CT measurement further demonstrated significant bone loss after bariatric surgery. Besides, histologic and Western blot analyses validated enhanced osteoclastogenesis and inhibited osteoblastogenesis and defective autophagy after surgery. The 16S rDNA gene sequencing suggested a significant alteration of gut microbiota composition in the RYGB group, and intervention with fecal microbiota from RYGB donor further determined that this kind of alteration contributed to the bone loss after RYGB. Meanwhile, C. butyricum might protect against this postoperative bone loss by promoting osteoblast autophagy. In summary, this study suggests novel mechanisms to clarify the skeletal response to bariatric surgery and provides a potential candidate for the treatment of bone disorder among bariatric patients. SIGNIFICANCE STATEMENT: The significance of this study is the discovery of obvious bone loss and defective autophagy after bariatric surgery. Besides, it is revealed that gut microbiota alterations could be the reason for impaired bone mass after bariatric surgery. Furthermore, Clostridium butyricum could alleviate the gut microbiota alteration-induced bone loss after bariatric surgery by promoting osteoblast autophagy.

Association of Probiotic Clostridium butyricum Therapy with Survival and Response to Immune Checkpoint Blockade in Patients with Lung Cancer.

Gut dysbiosis caused by antibiotics impairs response to immune checkpoint blockade (ICB). Gut microbiota is becoming an attractive therapeutic target for cancer. The Clostridium butyricum MIYAIRI 588 strain is a probiotic therapy used to improve symptoms related to antibiotic-induced dysbiosis in Japan. We hypothesized that probiotic Clostridium butyricum therapy (CBT) may affect the therapeutic efficacy of ICBs. We retrospectively evaluated 118 patients with advanced non-small cell lung cancer treated with ICBs at Kumamoto University Hospital (Kumamoto-shi, Kumamoto, Japan). Survival analysis comparing patients given CBT before and/or after ICB was conducted using univariate analyses and Cox proportional hazards regression models using propensity score. Propensity score analyses confirmed that probiotic CBT significantly prolonged progression-free survival (PFS) and overall survival (OS). Probiotic CBT significantly associated with longer PFS and OS even in patients who received antibiotic therapy. This study suggests that probiotic CBT may have a positive impact on therapeutic efficacy of ICB in patients with cancer.See articles by Hakozaki et al., p. 1243, and Peng et al., p. 1251.

Production of a neutralizing mouse-human chimeric antibody against botulinum neurotoxin serotype E.

A mouse-human chimeric antibody that can neutralize botulinum neurotoxin serotype E (BoNT/E) was developed. Variable regions of heavy and light chains obtained using a mouse hybridoma clone (E9-4) cDNA, which was selected on the basis of neutralizing activity against BoNT/E, were fused with the upstream regions of the constant counterparts of human kappa light and gamma 1 heavy chain genes, respectively. CHO-DG44 cells were transfected with these plasmids and a mouse-human chimeric antibody (EC94) was purified to examine binding and neutralizing activity against BoNT/E. EC94 exhibited the same levels of binding activities against BoNT/E as those of a parent mouse monoclonal antibody and neutralized more than 4,000 LD(50)/mg antibody. This chimeric antibody seems to be a useful candidate for infant botulism in which the use of passive immunotherapy is not planned so as to avoid serious events such as anaphylactic shock. We designed shuffling chimeric antibodies with replacement of V(H) or V(L) of EC94 with that of a chimeric antibody (AC24) that possessed neutralizing activity against BoNT/A. These shuffling antibodies did not exhibit neutralizing activity against either BoNT/E or BoNT/A.

An important role of interleukin-10 in counteracting excessive immune response in HT-29 cells exposed to Clostridium butyricum.

BACKGROUND: Clostridium butyricum has become increasingly important in preventing and treating intestinal inflammation. In the intestine it may increase the resistance of the gut to pathogen invasion via inducing the secretion of anti-inflammatory cytokines. Interleukin 10 (IL-10) plays a central role in preventing certain inflammatory diseases by down-regulating inflammatory cascades. In a previous study, we observed that the level of IL-10 mRNA was modulated by C. butyricum. The aim of this study was to investigate whether C. butyricum achieves its beneficial effects through IL-10. RESULTS: We treated HT-29 cells with anti-IL-10 (IL-10 antibody) or siIL-10 (IL-10 small interfering RNA) to disrupt IL-10. In both cases, the effects of C. butyricum-induced NF-κB activation and IL-8 expression were enhanced. We also found that neutralization or knockdown of IL-10 could induce apoptosis and necrosis of HT-29 cells treated with C. butyricum compared with control cells. CONCLUSIONS: These findings show that IL-10 serves an important role in C. butyricum-mediated immune protection, and in host recognition of C. butyricum.