Overlap of disorders of gut-brain interaction: a systematic review and meta-analysis

Treating disorders of brain-gut interaction with multidisciplinary integrated care. Moving towards a new standard of care

Disorders of brain-gut interaction (DGBI) are highly prevalent in our community with a negative burden on the quality of life and function. Symptoms are frequently food-induced, and psychological disorders are commonly co-morbid and contribute greatly to symptom severity and healthcare utilization, which can complicate management. Pathophysiological contributors to the development and maintenance of DGBI are best appreciated within the biopsychosocial model of illness. Established treatments include medical therapies targeting gastrointestinal physiology, luminal microbiota or visceral sensitivity, dietary treatments including dietary optimization and specific therapeutic diets such as a low-FODMAP diet, and psychological interventions. The traditional "medical model" of care, driven predominantly by doctors, poorly serves sufferers of DBGI, with research indicating that a multidisciplinary, integrated-care approach produces better outcomes. This narrative review explores the current evidence for multidisciplinary care and provides the best practice recommendations for physicians and healthcare systems managing such patients.

Prevalence and Characteristics of Covert/Minimal Hepatic Encephalopathy in Patients With Liver Cirrhosis: A Systematic Review and Meta-Analysis

INTRODUCTION

Covert/minimal hepatic encephalopathy (C/MHE) is the mildest form of hepatic encephalopathy (HE), but it is closely related to the quality of life and prognosis of patients with cirrhosis. Currently, the epidemiological data of C/MHE have not been well described.

METHODS

We searched the PubMed, Embase, and Cochrane Library databases for relevant articles. We performed a random-effects meta-analysis of proportions to estimate the pooled prevalence of C/MHE in patients with cirrhosis. We also examined potential risk factors for C/MHE by comparing characteristics of patients with and without C/MHE.

RESULTS

Finally, a total of 101 studies were included. The prevalence of C/MHE was 40.9% (95% confidence interval, 38.3%-43.5%) among patients with cirrhosis worldwide. The pooled C/MHE prevalence was 39.9% (95% confidence interval 36.7%-43.1%) based on studies using the psychometric HE score as a diagnostic tool. Meta-regression models showed that geographic region, sample size, mean age, sex ratio, and Child-Pugh classification were influencing factors for the heterogeneity of C/MHE prevalence. The presence of C/MHE was found to be associated with various factors including age, level of education, alcoholic etiology, Child-Pugh classification, MELD score, history of overt HE, presence of other complications, and laboratory tests related to impaired liver function.

DISCUSSION

This study reports detailed data on the prevalence of C/MHE as well as clinical features associated with C/MHE, suggesting that C/MHE is one of the most common complications of liver cirrhosis.

A Gpr35-tuned gut microbe-brain metabolic axis regulates depressive-like behavior

Gene-environment interactions shape behavior and susceptibility to depression. However, little is known about the signaling pathways integrating genetic and environmental inputs to impact neurobehavioral outcomes. We report that gut G-protein-coupled receptor, Gpr35, engages a microbe-to-brain metabolic pathway to modulate neuronal plasticity and depressive behavior in mice. Psychological stress decreases intestinal epithelial Gpr35, genetic deletion of which induces depressive-like behavior in a microbiome-dependent manner. Gpr35-/- mice and individuals with depression have increased Parabacteroides distasonis, and its colonization to wild-type mice induces depression. Gpr35-/- and Parabacteroides distasonis-colonized mice show reduced indole-3-carboxaldehyde (IAld) and increased indole-3-lactate (ILA), which are produced from opposing branches along the bacterial catabolic pathway of tryptophan. IAld and ILA counteractively modulate neuroplasticity in the nucleus accumbens, a brain region linked to depression. IAld supplementation produces anti-depressant effects in mice with stress or gut epithelial Gpr35 deficiency. Together, these findings elucidate a gut microbe-brain signaling mechanism that underlies susceptibility to depression.

Efficacy and Safety of STW 5-II for Functional Dyspepsia Treatment: A Patient Data-Based Meta-Analysis

INTRODUCTION

Functional dyspepsia (FD) is a chronic relapsing gastroduodenal disorder with limited treatment options. Herbal products, like the six-herb combination STW 5-II, can target multiple FD gastrointestinal symptoms. In this meta-analysis, we evaluated the efficacy and safety of STW 5-II for overall FD, and key symptoms, based on Rome IV criteria.

METHODS

We systematically screened the literature for randomized controlled clinical studies testing STW 5-II in FD. Meta-analysis was performed using data from individual patients with at least one key FD symptom (fullness, early satiety, or epigastric pain) of at least moderate severity at baseline. ANCOVA-based meta-analyses were performed on improvements in the total symptom sum score, and single symptoms, after 4 and 8 weeks. Safety data were analyzed by calculating odds ratios for all adverse events.

RESULTS

Four randomized controlled trials, including 613 patients, were identified, and two were eligible for efficacy analysis. STW 5-II significantly improved the FD symptom sum score (mean difference of 1.74 after 4 weeks and 2.07 after 8 weeks) and key FD symptoms of fullness (0.28 and 0.29), early satiety (0.25 and 0.26), and epigastric/upper abdominal pain (0.26 and 0.3). Treatment-related or severe adverse events did not differ between STW 5-II and placebo.

CONCLUSION

The results support that STW 5-II significantly improves FD symptoms after 4 and 8 weeks of treatment with no difference in relation to safety signals compared to placebo. Thus, STW 5-II can be considered an effective and safe treatment option for FD.

Microbiome: The Next Frontier in Psychedelic Renaissance

The psychedelic renaissance has reignited interest in the therapeutic potential of psychedelics for mental health and well-being. An emerging area of interest is the potential modulation of psychedelic effects by the gut microbiome-the ecosystem of microorganisms in our digestive tract. This review explores the intersection of the gut microbiome and psychedelic therapy, underlining potential implications for personalized medicine and mental health. We delve into the current understanding of the gut-brain axis, its influence on mood, cognition, and behavior, and how the microbiome may affect the metabolism and bioavailability of psychedelic substances. We also discuss the role of microbiome variations in shaping individual responses to psychedelics, along with potential risks and benefits. Moreover, we consider the prospect of microbiome-targeted interventions as a fresh approach to boost or modulate psychedelic therapy's effectiveness. By integrating insights from the fields of psychopharmacology, microbiology, and neuroscience, our objective is to advance knowledge about the intricate relationship between the microbiome and psychedelic substances, thereby paving the way for novel strategies to optimize mental health outcomes amid the ongoing psychedelic renaissance.