The gastrointestinal tract is home to trillions of diverse microorganisms collectively known as the gut microbiota, which play a pivotal role in breaking down undigested foods, such as dietary fibers. Through the fermentation of these food components, short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate are produced, offering numerous health benefits to the host. The production and absorption of these SCFAs occur through various mechanisms within the human intestine, contingent upon the types of dietary fibers reaching the gut and the specific microorganisms engaged in fermentation. Medical literature extensively documents the supplementation of SCFAs, particularly butyrate, in the treatment of gastrointestinal, metabolic, cardiovascular, and gut-brain-related disorders. This review seeks to provide an overview of the dynamics involved in the production and absorption of acetate, propionate, and butyrate within the human gut. Additionally, it will focus on the pivotal roles these SCFAs play in promoting gastrointestinal and metabolic health, as well as their current therapeutic implications.

The gastrointestinal tract is colonized by trillions of different microorganisms, named the gut microbiota, which is key to degrade undigested food such as dietary fibers. The fermentation of these food components leads to the production of short-chain fatty acids (SCFA) acetate, propionate, and butyrate, which exploit several beneficial roles for the host’s health. Their production and absorption happen in different ways in the human intestine and depend on the type of dietary fiber reaching the gut and the microorganisms involved in the fermentation. The supplementation of SCFAs, mostly butyrate, in treating gastrointestinal, metabolic, cardiovascular, and gut-brain-related diseases has been reported in the medical literature. This review aims to give an overview of the production and absorption dynamics of acetate, propionate, and butyrate in the human gut, with a final focus on the role played by these SCFAs on gastrointestinal and metabolic health and the present therapeutic implications.

The esophagus, traditionally viewed as a sterile conduit, is now recognized as a dynamic habitat for diverse microbial communities. The emerging evidence suggests that the esophageal microbiota plays an important role in maintaining esophageal health and contributing to disease. The aim of this systematic review was to synthesize the current knowledge on the esophageal microbiota composition, its variation between healthy individuals and those with esophageal diseases, and the potential mechanisms through which these microorganisms influence esophageal pathology. A systematic literature search was conducted using multiple databases, including PubMed, Scopus, and Web of Science, to identify relevant studies published up to July 2024. The inclusion criteria encompassed original research articles that used molecular techniques to characterize the esophageal microbiota in human subjects, comparing healthy individuals with patients affected by esophageal conditions such as gastroesophageal reflux disease (GERD), Barrett’s esophagus, eosinophilic esophagitis, and esophageal cancer. The primary outcomes were the composition and diversity of the esophageal microbiota, and the secondary outcomes included the correlations between microbial profiles and disease states. The esophageal microbiota of healthy individuals was dominated by Gram-positive bacteria, particularly Streptococcus. Conversely, the esophageal microbiota is considerably altered in disease states, with decreased microbial diversity and specific microbial signatures associated with these conditions, which may serve as biomarkers for disease progression and as targets for therapeutic intervention. However, the heterogeneous study designs, populations, and analytical methods underscore the need for standardized approaches in future research. Understanding the esophageal microbiota’s role in health and disease could guide microbiota-based diagnostics and treatments, offering novel avenues for managing esophageal conditions.

Background/Objectives: Restorative proctocolectomy with ileo-anal pouch anastomosis (IPAA) remains the preferred surgical treatment for ulcerative colitis (UC). However, complications like pouchitis can occur. This study aimed to describe patients who underwent IPAA for inflammatory bowel disease (IBD) at Padua Hospital from 2005 to 2023 and identify risk factors for pouchitis. Secondary objectives included evaluating the effectiveness of biological therapy in chronic antibiotic-refractory pouchitis (CARP), Crohn’s disease of the pouch (CDP), and Crohn’s-like inflammation of the pouch (CDLPI), and assessing risk factors for pouch failure. Methods: This retrospective, observational study included 109 patients whose data were collected from medical records. Univariate logistic regression was used to analyze associations between preoperative and postoperative factors and outcomes such as acute pouchitis and pouch failure. The effectiveness of biological therapy was assessed by measuring changes in the Pouchitis Disease Activity Index (PDAI) and the Modified Pouchitis Disease Activity Index (mPDAI) over a 12-month treatment period. Results: Univariate logistic regression revealed significant associations between preoperative extraintestinal manifestations (OR 3.569, 95% CI 1.240–10.720), previous diagnosis of Crohn’s disease (OR 10.675, 95% CI 1.265–90.089), and transmural inflammation at cross-sectional imaging before surgery (OR 3.453, 95% CI 1.193–9.991) with an acute pouchitis risk. Pouch failure was significantly associated with a previous diagnosis of Crohn’s disease (OR 9.500, 95% CI 1.821–49.571) and post-surgical fistulas (OR 41.597, 95% CI 4.022–430.172). Biological therapy led to a significant reduction in the PDAI score in patients with CARP, decreasing from a median of 10 to 4 (p = 0.006). Similarly, in patients with CDP or CDLPI, the mPDAI score was significantly reduced from a median of 9 to 1 (p = 0.034), with remission achieved in 5/6 (83.3%) of these patients. Conclusions: This study provides valuable insights into the management of IPAA patients and highlights the importance of early identification and treatment of risk factors for pouchitis and failure. Biological therapy demonstrated significant effectiveness in reducing disease activity in patients with CARP, CDP, and CDLPI, suggesting its role as a crucial component in managing these complications.

Background: Upadacitinib (UPA), a selective anti-JAK1 agent, obtained refundability from the Italian National Health System in July 2023 for its use in patients with ulcerative colitis (UC) refractory to other therapies, including anti-TNF-α, anti-integrins, and ustekinumab. At present, no Italian data are available about its effectiveness and safety in the real world. Methods: A retrospective assessment of clinical and endoscopic activity was performed according to the Mayo score. The primary endpoints were to evaluate the effectiveness and safety of UPA. Results: We included 202 consecutive UC patients (M/F 119/83, median age 42). The clinical remission and clinical response rates were 45.5% (92/202) and 63.5% (128/202), respectively, at 8 weeks and 60.2% and 81.7%, respectively, at the end of the follow-up. Clinical remission was achieved more frequently when UPA was used as a first-line rather than a second-/third-line treatment (p = 0.609). Mucosal healing was reported in 84.6% of patients at the median follow-up time. Adverse events occurred in six patients (2.5%), whereas four patients (2%) underwent colectomy. Conclusions: This large real-world study shows that UPA is an effective and safe treatment for UC patients.

Background: Risankizumab (RZB) is an anti-interleukin 23 (anti-IL-23) approved for the treatment of Crohn disease (CD). Study question: We aimed to evaluate the effectiveness and safety of RZB in the treatment of CD in real-world settings. Study design: We performed a retrospective review of a multicentre consortium of patients with CD treated with RZB. Measures and Outcomes: Coprimary outcomes were clinical remission at week 12, 24, and 52 (Harvey–Bradshaw Index score of ≤4), and safety. Secondary outcomes included steroid-free clinical remission, clinical response, and endoscopic remission at 52 weeks. Results: A total of 487 patients were included. The median follow-up was 24 (interquartile range: 16–38) weeks. A total of 372 (76.4%) patients achieved clinical remission at maximal follow-up. According to the treatment line in which RZB was administered, clinical remission occurred in 115/134 (85.8%) patients on second-line therapy, 112/153 (73.2%) on third-line therapy, and 145/200 (72.5%) on fourth-line therapy, with a significant difference ( P = 0.010). Adverse events occurred in 60 patients (12.6%) during follow-up; most of them were mild (50/60, 83.3%). Regarding the secondary outcomes: steroid-free clinical remission was achieved in 342 (71.8%) patients, and clinical response was observed in 443 (91.0%) patients. Six (1.2%) patients underwent surgery during follow-up. Mucosal healing was achieved in 34/67 (50.7%) patients. Conclusions: In this extensive, real-world study, RZB was effective and well tolerated in an advanced-therapy–exposed population of patients with CD and associated with favorable clinical and endoscopic outcomes.