Learning Outcomes
By the end of this section, you should be able to:
- 4.4.1 Describe the homeostasis of gut health.
- 4.4.2 Describe the impact of diet on gut health.
- 4.4.3 Identify the impact of pharmacology on gut health.
- 4.4.4 Identify pathophysiology and gut health.
Gut Health Homeostasis
For healthy digestion and absorption of food and nutritional health, the gut must maintain a healthy homeostasis, the equilibrium maintained in the body through physiological processes and evidenced by intestinal microbiota growth. The nurse plays an important role in client education that leads to optimal nutritional health.
The composition of the gut’s microbial growth has a strong impact on the homeostasis of the gut. When the gut is not in a state of homeostasis, the imbalance that results can cause dysbiosis, a disruption to the gut microbiome. Many diseases have been linked to dysbiosis, including anxiety, depression, hypertension, cardiovascular disease, cancer, inflammatory bowel disease, obesity, and diabetes, so the impact of an unhealthy gut surpasses just gastrointestinal health (Afzaal et al., 2022).
To maintain proper gut homeostasis, bacterial growth requires energy in the form of adenosine triphosphate and oxygen (Lee et al., 2022). Dietary factors, antibiotics, and underlying host conditions can reduce oxygen consumption in the colonic epithelium, thereby reducing the available oxygen to the indigenous microbes.
The microbiota of the gut has many functions in the body. These bacterial residents help control nutrient metabolism, defend against pathogens, contribute to carbohydrate digestion, synthesize methane from hydrogen processed by bacterial metabolism, neutralize carcinogens, and synthesize biotin, folate, and vitamin K (Afzaal et al., 2022).
Diet and Gut Health
Diet directly impacts the health of microbial growth (Lee et al., 2022). There are numerous foods that have a positive impact on gut health. For example, fiber, water intake, fruits and vegetables, whole grains, and an overall well-balanced diet have shown positive effects. Yogurt is known to have a positive impact because it contains active bacterial cultures, which have been shown to be supportive of the gut microbiome environment (Stanford Medicine Children’s Health, 2023a). High-fat diets, in contrast, have been shown to have a negative impact. They tend to contribute to diabetes, obesity, metabolic syndrome, and colon cancer (Afzaal et al., 2022; Baton Rouge General, 2023). In addition, high sodium intake and alcohol use can contribute to dysbiosis and have been linked to hypertension.
A nurse can make a direct impact on client health by educating clients on why diet, gut microbiota, and homeostasis are important. The nurse should speak to the specific reasons why fiber, water, probiotics, and whole grains are valuable in a diet and why saturated fats, alcohol, and sodium are areas of concern. The nurse should discuss with the client so they understand which types of food to increase or decrease. Table 4.3 lists common foods and their impact on the gastrointestinal system.
Food | Impact on Gastrointestinal System |
---|---|
Fresh fruits and vegetables, lentils, kidney beans, split peas, chickpeas, quinoa, oats, popcorn, almonds, chia seeds, sweet potatoes, and dark chocolate | These foods are high in fiber and help maintain gut homeostasis, reduce cholesterol, promote healthy weight through satiety, reduce constipation by adding bulk to stool, and possibly reduce gastrointestinal cancer risks due to potential antioxidant properties (Gunnars, 2020; Moffitt Cancer Center, 2023). |
Water | Increasing fiber requires increasing water in the diet to ensure there is sufficient water in the stool to account for the added bulk. |
Saturated fats (found in fatty cuts of meat, pies, sausage, butter, lard, cheddar cheese, ice cream, sour cream, biscuits, cakes, pastries, milk chocolate confectionaries, palm oil, coconut oil, and coconut cream) | Saturated fats can lead to gut imbalance (Afzaal et al, 2022), raise bad cholesterol levels (NHS, 2023), and increase colon cancer risks (Baton Rouge General, 2023). |
High-sodium foods (breads; pizza; sandwiches; deli meats and cured meats; cheese; soups; burritos and tacos; snacks like chips, popcorn, and pretzels; chicken; and omelets) | High amounts of sodium can upset the homeostasis of the gut by increasing dehydration. |
Pharmacology and Gut Health
Pharmacology and nutrition are interdependent because they rely on the same body processes. When the body lacks nutrients, the body’s ability to utilize certain drugs is impacted (Bhupathiraju & Hu, 2023). A lack in nutrients also impacts the body’s ability to properly dispose of toxins from drugs and digestion waste. The nutritional state of a client greatly impacts the ability of their medications to be properly metabolized, used, and excreted.
Probiotics, such as Lactobacillus, are supplements that are known to have positive impacts on the gut microbiome. These are useful in helping clients with dietary restrictions or who are taking certain medications that interfere with gut health. These supplements should be taken in combination with a healthy diet because they do not prevent gastrointestinal issues on their own but rather support healthy practices.
There are medications that can help and hurt the microbiota of the gut. Antibiotics are a well-known culprit for altering microbial growth. Long-term antibiotic use has been linked to Clostridium difficile (C. diff) infection and colon cancer. When a client needs antibiotics for longer than three days, it is common practice that they also be given a probiotic to counteract some side effects and the possibility of infection.
There are other medications that are lesser known for being harmful. They include:
- Proton pump inhibitors to treat gastroesophageal reflux disease, which can cause enteric infections like C. diff (Weersma et al., 2020)
- Metformin, used to treat diabetes, which can increase Escherichia coli (E. coli) in the intestines and lower other bacteria, causing imbalances in the microbiome
- Statins to treat hyperlipidemia, which can cause constipation or diarrhea, upsetting the homeostasis in the gut
- Antidepressants, which can kill off beneficial gut bacteria and alter the normal microbiome of the gut
- Opioids to treat chronic pain, which can cause severe bouts of constipation, upsetting the microbiome and preventing the excretion of wastes from the body
- Laxatives, which can cause disruption of the microbiome through electrolyte disturbances, dehydration, and mineral deficiencies
Pathophysiology and Gut Health
Gut health and its impact on the body are often discussed in relation to bidirectional crosstalk at an axis point (the two-way communication that is focused at a specific intersection) between body systems that regulate health relative to one another (Tilg et al., 2022). The gut has many of these axes that connect it to the liver, brain, lung, nervous system, sensory system, etc. The following section will look at the gut and its connection with the liver, brain, and lung.
Gut-Liver, Gut-Brain, and Gut-Lung Axis
Gut-liver axis communication happens between nutrients, metabolites, microbial antigens, and bile acids within a microbial community (Ding et al., 2020; Tilg et al., 2022). A disturbance in this gut-liver network has been linked to an increase in hepatic inflammation and hepatic encephalopathy and decompensation of liver cirrhosis (Klein, 2022).
The gut-brain axis has been shown to have many devastatingly negative effects. The gut has been shown to produce neuroactive compounds that modulate metabolism and immunity (Benakis & Liesz, 2022), which are essential components to healing after a stroke. Because a stroke leads to intestinal dysmotility and permeability of the intestinal barrier, and thus decreased metabolism and depressed immunity, stroke victims often have impaired healing. Table 4.4 outlines some other diseases connected to the gut-brain connection.
Disease | Impact |
---|---|
Parkinson’s disease | Overgrowth of intestinal bacteria results in an increase in opportunistic pathogens, causing the neurotransmitter L-dopa to be decreased (Wallen et al., 2022). Parkinson’s disease is directly impacted by the availability of L-dopa, and symptoms are worsened when the availability is decreased. |
Multiple sclerosis | Overgrowth of certain gut bacteria causes an imbalance in homeostasis; exacerbations and advancement of the disease can be affected (eBioMedicine, 2022; French, 2022). |
Alzheimer’s disease | Clients with Alzheimer’s disease are shown to demonstrate excessive production and aggregation of amyloid-beta peptides that lead to extracellular plaque formation (Sidharthan, 2022). Gut microbiota health impacts the disease because when it is unbalanced, it releases more of certain by-products that can alter inflammatory cytokine-signaling pathways, leading to amyloid-beta peptide accumulation. |
Mental health | A link has been found between systemic inflammations and anxiety, depression, and other mental illnesses (GI Associate and Endoscopy Center, 2022a). The health of the gut has a large impact on the inflammatory state of the body. It also has a key function in the release of many neurotransmitters, one of which is serotonin, an important mood neurotransmitter. |
Huntington’s disease | When the gut microbiota is unbalanced, there is an influence on mood, cognition, and sleep, which are already negatively impacted by this disease (Wasser et al., 2020). |
Due to the recent COVID-19 pandemic, the gut-lung axis has been more recently explored. Overall, the gut’s role in the health of the body’s overall immunity and the reduction of systemic inflammation has been applied to COVID-19 infection. The resulting acute respiratory distress syndrome that is a life-threatening effect of the virus is caused by an autoimmune-response-mediated inflammation in the lungs. Overall rates of mortality with COVID-19 are markedly higher for those admitted to the intensive care unit, and those who have gastrointestinal symptoms in conjunction with their respiratory symptoms are much more likely to need intensive care, making gastrointestinal issues a determinant of prognosis (Chen et al., 2020; Cleveland Clinic, 2022b; Ye et al., 2020; Ouali et al., 2021). Long-haul COVID-19 has also become more prevalent. Because clients who have gastrointestinal symptoms with COVID-19 infection have a longer detoxification time after infection, they are at a higher risk for developing long-haul COVID than those without gastrointestinal symptoms.