Bad "Good" Bile Acids and Gut Microbiota Dysbiosis in Inflammatory Bowel Disease: Mice and Humans Are Not the Same

Vinegar-processed frankincense ameliorates ulcerative colitis by targeting BSH-active bacteria preference-mediated GDCA hydrolysis

ETHNOPHARMACOLOGICAL RELEVANCE

Frankincense, is extensively used in both traditional Chinese medicine (TCM) and Indian practices for the treatment of ulcerative colitis (UC). In TCM, it is typically subjected to process with vinegar, which is believed to enhance its therapeutic efficacy. However, the underlying mechanism has yet to be elucidated.

AIM OF THE STUDY

To elucidate the underlying mechanism of frankincense vinegar processing from the perspective of bile salt hydrolase (BSH)-active bacteria preference and glycodeoxycholic acid (GDCA) hydrolysis.

MATERIALS AND METHODS

Dextran sodium sulfate (DSS)-induced UC model was used to elucidate the superior improving effects of vinegar-processed frankincense (PF). 16S rRNA and metagenomic sequencing along with ultra-high performance liquid chromatography-triple quadrupole mass spectroscopy (UHPLC-TQ-MS) were employed to reveal the differential bacteria and its related disturbance of GDCA. The effects of PF and GDCA on BSH-active bacteria were confirmed using real-time quantitative polymerase chain reaction (RT-qPCR) and in vitro experiments. Finally, the pro-inflammatory effects of GDCA and the mechanisms by which PF ameliorates UC were verified by establishing a UC pseudo-sterile mice model with GDCA intervention.

RESULTS

PF exhibited remarkable mitigating effects on UC (P < 0.05 or P < 0.01). Specifically, PF enhanced the BSH activity of Bifidobacterium longum and Lactobacillus acidophilus (P < 0.01), thereby promoting their dissociation efficiency toward glycine-conjugated bile acids (G-CBAs), particularly GDCA (P < 0.01). Furthermore, PF reduced GDCA levels by regulating the dissociation efficiency of Bifidobacterium longum and Lactobacillus acidophilus toward GDCA, thereby alleviating GDCA-induced exacerbation of UC.

CONCLUSION

PF exhibits its superior amelioration effects on UC by enhancing the dissociation efficiency of Bifidobacteruum longum and Lactobacillus acidophilus towards G-CBAs, particularly GDCA.

Determination of Bile Acids in Canine Biological Samples: Diagnostic Significance

The comprehensive examination of bile acids is of paramount importance across various fields of health sciences, influencing physiology, microbiology, internal medicine, and pharmacology. While enzymatic reaction-based photometric methods remain fundamental for total BA measurements, there is a burgeoning demand for more sophisticated techniques such as liquid chromatography-tandem mass spectrometry (LC-MS/MS) for comprehensive BA profiling. This evolution reflects a need for nuanced diagnostic assessments in clinical practice. In canines, a BA assessment involves considering factors, such as food composition, transit times, and breed-specific variations. Multiple matrices, including blood, feces, urine, liver tissue, and gallbladder bile, offer insights into BA profiles, yet interpretations remain complex, particularly in fecal analysis due to sampling challenges and breed-specific differences. Despite ongoing efforts, a consensus regarding optimal matrices and diagnostic thresholds remains elusive, highlighting the need for further research. Emphasizing the scarcity of systematic animal studies and underscoring the importance of ap-propriate sampling methodologies, our review advocates for targeted investigations into BA alterations in canine pathology, promising insights into pathomechanisms, early disease detection, and therapeutic avenues.

New insights into the interplay between intestinal flora and bile acids in inflammatory bowel disease

Intestinal flora plays a key role in nutrient absorption, metabolism and immune defense, and is considered to be the cornerstone of maintaining the health of human hosts. Bile acids synthesized in the liver can not only promote the absorption of fat-soluble substances in the intestine, but also directly or indirectly affect the structure and function of intestinal flora. Under the action of intestinal flora, bile acids can be converted into secondary bile acids, which can be reabsorbed back to the liver through the enterohepatic circulation. The complex dialogue mechanism between intestinal flora and bile acids is involved in the development of intestinal inflammation such as inflammatory bowel disease (IBD). In this review, the effects of intestinal flora, bile acids and their interactions on IBD and the progress of treatment were reviewed.