Functional Dyspepsia: A Disorder of Gut-Brain Interaction

Disorders of gut-brain interaction (DGBIs), formerly known as functional gastrointestinal disorders, have a complex pathophysiology, with the gut-brain bidirectional communication playing a key role, as well as the relationship between food consumption and the triggering of symptoms such as abdominal pain and altered intestinal motility.^1-3 Functional dyspepsia (FD) is one DGBI, characterized by epigastric pain or burning, bothersome postprandial fullness, or early satiation without a definitive organic cause.⁴ Many patients with FD also experience other troublesome symptoms, including bloating, nausea after eating, and excessive belching.⁵ FD has been subdivided into meal-related dyspepsia, or postprandial distress syndrome (PDS), and meal-unrelated dyspepsia, or epigastric pain syndrome (EPS); however, overlap between the two conditions has been reported.⁴

FD prevalence estimates vary worldwide, with higher rates noted in Western countries, including the United States.⁵ Since dyspepsia may present with a multitude of symptoms, FD is a diagnosis of exclusion, and clinicians are encouraged to look for red flags that are clinical indicators of a possible serious underlying condition.⁴ While the pathogenesis of FD continues to be studied, this DGBI has been associated with:^4,6,7

• Sociopsychological factors such as stress, anxiety, depression, and stressful interpersonal relationships.
• Biological mechanisms such as gastroduodenal dysfunction and inflammation, impaired duodenal mucosal integrity, and visceral hypersensitivity.

Treatment Strategies – Modifiable Lifestyle Factors

The impaired quality of life experienced by patients with this condition implies the need for a definitive diagnosis followed by treatment for the duration of the symptomatic interval. However, the causes of FD are varied and complex, emphasizing the need for a personalized approach. Lifestyle-based as well as pharmaceutical-based therapeutic options have been recommended as first-line treatments.⁸ In addition to nutrition, exercise, and establishing a collaborative patient-practitioner relationship,⁸ potential adjunctive or alternative non-pharmacologic therapies include psychotherapy, herbal supplementation, lifestyle modification, acupuncture, and electrical stimulation.⁹

Consideration of a patient’s lifestyle patterns and habits is critical for a successful treatment strategy. Sleep dysfunction and disorders are common in patients with FD,⁶ which may exacerbate other symptoms and reduce quality of life. Psychiatric comorbidities such as depression and anxiety are another feature of DGBIs like dyspepsia.¹⁰ Research suggests that psychological interventions may benefit patients with FD,¹¹ and implementing adjunctive mind-body or relaxation therapies may also help reduce FD symptoms.^12,13

STRESS AND SOCIAL SUPPORT

Research suggests that FD may lead to an increase in anxiety levels, regardless of the type of disease. A 2019 cross-sectional study compared depression and anxiety levels of patients diagnosed specifically with either PDS or EPS with healthy volunteers and found increased anxiety for both EPS and PDS patients.¹⁴ In addition, those with PDS showed significantly lower rates of general health and social functioning as well as elevated depression levels compared to patients with EPS.¹⁴

A 2019 prospective randomized controlled single-blind study with 100 patients investigated the effects of comfort care on FD symptoms, gastric motility, and mental state of patients.⁷ The study’s results suggested that comfort care reduces FD symptoms, increases gastric emptying rate, improves gastric motility, relieves patients’ depression and anxiety, and promotes the rehabilitation of the disease. In this study, comfort care was implemented as medical care that:⁷

• Identified the patient’s stressors.
• Alleviated those stress responses.
• Provided psychological and social support.

NUTRITION AND EXERCISE

Nutrition and dietary patterns are also important components when implementing treatment strategies based on modifiable lifestyle factors. A 2020 systematic review found that a higher consumption of ultra-processed food was associated with a range of chronic diseases, including DGBIs in adults.¹⁵ Since certain foods may trigger increased dyspeptic symptoms for some patients, a diet low in FODMAPs may be helpful for FD patients.^16,17 Further, eating small, frequent meals may be an accessible lifestyle-based strategy to help some patients initially find relief from dyspeptic symptoms.^4,8,18

For patients with FD, normal exercise routines and physical activity may be negatively impacted. In a 2020 population-based study, subjects with FD reported significantly less walking and lower frequency of exercising.¹⁹ Of interesting note, those with PDS reported less vigorous exercise, but not those with EPS.¹⁹ Studies suggest that treatments that include moderate exercise routines may benefit some patients with FD.^13,20 A 2021 randomized controlled trial (n=112 patients with FD) found that engaging in aerobic exercise for six weeks (five times per week; 30 minutes per session) improved dyspepsia symptom severity scores as well as symptoms of depression and anxiety to a greater extent than conventional treatment alone.²⁰

The Functional Medicine Approach

The functional medicine model emphasizes the necessity for personalized treatment strategies and for considering modifiable lifestyle factors in addressing potential underlying causes of FD and other DGBIs such as gastroesophageal reflux disease (GERD) and irritable bowel syndrome (IBS). A wide range of gastrointestinal (GI) symptoms and conditions may be treated starting with the functional medicine DIGIN framework that helps clinicians assess the overall digestive system health of their patients. Further, IFM’s 5R framework (Remove, Replace, Repopulate, Repair, and Rebalance) may be implemented to help support and heal the digestive tract. Functional medicine clinicians use these tools as well as the functional medicine matrix and timeline to map out a patient’s health journey, organize their clinical imbalances, and help develop an individualized treatment strategy. These strategies may include identifying and reducing potential food and stress-related triggers, applying therapeutic food plans, and providing support as the patient continues on their health journey.

IFM teaches clinicians the foundational background, insight, and in-depth clinical thinking to confidently work-up and treat patients who may present with conditions, signs, and symptoms indicative of GI dysfunctions. Learn to recognize and treat the most important antecedents and triggers of GI dysfunction and implement therapeutic strategies at IFM’s GI Advanced Practice Module (APM).