Gerald J. Holtmann

Digestive diseases (Basel, Switzerland) • December 20, 2024

Gerald Holtmann, Md Moniruzzaman, Ayesha Shah

Background: The gut-brain axis is a bidirectional communication pathway connecting the gastrointestinal tract and the brain. Disorders of gut-brain interaction (DGBI) manifest as highly prevalent gastrointestinal disorders such as irritable bowel syndrome (IBS) or functional dyspepsia (FD). Conclusions: The initial focus of DGBI research was on the effects of psychological stress on digestive functions like gastrointestinal motility, or secretion of gastric acid and pancreatic enzymes. Concepts related to DGBI have expanded in recent decades. Activation of mucosal or systemic immune functions has been observed in DGBI, and it is established that the gastrointestinal microbiome can alter mucosal integrity and permeability, leading to pro-inflammatory cytokine release that affects brain function. Pharmacologic treatments (e.g., tricyclic antidepressants) and non-pharmacologic interventions (e.g., cognitive behavioral therapy) are now standard for DGBI patients. Advances in culture-independent methods to study gastrointestinal microbes reveal new insights into DGBI and gut microbiota appear to play a crucial role in modulating the gut-brain axis and regulating various bodily functions. Conclusions: DGBI are highly prevalent. Research in this field has evolved from studying the effects of psychological stress to recognizing the significant role of the gut microbiome and its metabolites in mucosal integrity and immune responses.

Digestive And Liver Disease : Official Journal Of The Italian Society Of Gastroenterology And The Italian Association For The Study Of The Liver • March 19, 2025

Md Moniruzzaman, Ayesha Shah, Mark Morrison, Natasha Koloski, Kok Gwee, Minhu Chen, Yongsung Kim, Kana Ayaki, Thomas Efferth, Gerald Holtmann

Disorders of gut-brain interaction (DGBI), such as functional dyspepsia (FD) and irritable bowel syndrome (IBS), affect about one-third of the global population. Many patients turn to traditional and herbal medicines for relief, given the lack of effective therapies. This review assesses the clinical and preclinical evidence for herbal treatments used for patients with DGBI. Placebo-controlled trials show that specific herbal preparations, including peppermint oil, ginger, and commercial formulations like STW-5, ZZKZ and Rikkunshito significantly improve gastrointestinal symptoms. Their effectiveness likely arises from various mechanisms, such as alterations in gastrointestinal motility, desensitization of visceral sensory function, and suppression of low-grade mucosal or systemic inflammation. Recent studies of the effects of herbal extracts on the gastrointestinal microbiome also implicate microbial involvement in their effectiveness. Most herbal preparations contain multiple bioactive compounds to address various disease mechanisms, and there remains a significant gap in dose-response studies for optimizing therapeutic outcomes.

Therapeutic Advances In Gastroenterology • March 12, 2025

Richard Kellermayer, Peter Lewindon, Cynthia Buness, James Tabibian, Kevin Johnson, Shamita Shah, Parambir Dulai, Ahmad Ali, Ayesha Shah, Gerald Holtmann, Harland Winter

Public Health Research & Practice • February 20, 2025

Nicole Marinucci, Natasha Koloski, Amanda Whaley, Rachael Bagnall, Ayesha Shah, Belinda Goodwin, Gerald Holtmann

Objectives Promoting the Australian National Bowel Cancer Screening Program in general practice has been identified as an effective strategy to increase participation rates. Despite the positive influence general practitioners (GPs) have on patient decision-making, program endorsement is not routinely included within the national program's policy and practice. The aim of this study was to gain a comprehensive understanding of knowledge, health promotion strategies and the challenges/opportunities for general practice staff to support patient participation and navigation through the National Bowel Cancer Screening Program pathways. Study type A 52-item online cross-sectional survey. Methods A total of 320 general practice clinics in the Metro South Hospital and Health Service, Queensland, Australia received a direct invitation via email to participate. The survey contained items on knowledge, health promotion strategies and challenges/opportunities to endorse participation in the National Bowel Cancer Screening Program, including enquiry about the utilisation of electronic medical records. Results Eighty-eight individuals participated, including GPs, practice managers and practice nurses. Of GPs, 96.2% indicated they were likely to promote the National Bowel Cancer Screening Program to patients. Few participants used systems to identify/notify patients due for screening, and over half indicated that Medicare reimbursements (56.8%) and electronic systems for identifying eligible or overdue patients (53.4%) would support their ability to promote the National Bowel Cancer Screening Program in routine practice. Conclusion Early detection and treatment of bowel cancer is a public health priority in Australia and internationally. Findings highlight the willingness of staff to promote participation; however, the need for incentivisation and streamlined software integration to identify and prompt eligible patients to screen through the National Bowel Cancer Screening Program remains. These findings contribute new evidence regarding the resources, preferences and system-level requirements needed to support routine GP endorsement of the National Bowel Cancer Screening Program.

Neurogastroenterology And Motility • January 21, 2025

Bert Broeders, Esther Colomier, Florencia Carbone, Magnus Simrén, Tao Bai, Jinsong Liu, Chloé Melchior, Guillaume Gourcerol, Kee-huat Chuah, Khoo Hui, Sanjiv Mahadeva, Kewin Tien Siah, Kok-ann Gwee, Peter Lipták, Peter Banovcin, Gerald Holtmann, Natasha Koloski, Marilia Carabotti, Bruno Annibale, Hidekazu Suzuki, Masaya Sano, Takashi Ueda, Hassan Shahoon, Peyman Adibi, Cedric Van De Bruaene, Tim Vanuytsel, Jan Tack

Background: Nausea can coexist in functional dyspepsia (FD) but the literature is poor in reporting whether this symptom is mainly triggered by meal ingestion. Moreover, the prevalence of nausea in FD is understudied. Methods: Adult patients with a disorder of gut-brain interaction (DGBI) recruited in secondary and tertiary care facilities completed the enhanced Asian Rome IV questionnaire with additional questions to address the relationship between nausea and food intake. A comparison of nausea and the prevalence of meal-related nausea was made among FD subgroups and with chronic nausea and vomiting syndrome (CNVS), both according to Rome IV criteria. Results: Of the 1075 DGBI patients that completed the survey, 443 were classified as having FD and 44 other patients fulfilled diagnostic criteria for CNVS. The PDS-EPS overlap group had a higher prevalence of nausea compared to PDS and EPS patients. In PDS patients with nausea, nausea was significantly more often meal-related (than in PDS-EPS overlap, EPS, and CNVS patients). All patients with meal-related nausea reported that nausea started mostly (> 85% of times) within 60 min after the meal. When comparing western and eastern participating centers, nausea was more prevalent in patients from western sites. Conclusions: Nausea is a highly prevalent symptom in FD with a higher prevalence in the PDS-EPS overlap group. However, meal-related nausea is more common in PDS. The pathophysiology of nausea in FD and its implication for medical treatment require further studies.