A medical surgeon once described to me the kind of things he sees when operating on the intestines and internal organs of patients and I was shocked. He said that in more than half of the cases, the intestines of the patients are in such wretched and irredeemable condition that he is not surprised as to why they are in such poor health and bad mood. Abnormal intestinal conditions can significantly impact both mental health and the development or worsening of other diseases. Dr. J. H. Kellogg, a health reformer and surgeon in the late 19th and early 20th centuries, made several notable observations during his surgeries:
Kellogg saw large amounts of impacted (pressed together and hardened) faecal matter, believed to result from low-fiber diets (Kellogg, 1910). These were food that were supposed to have digested and passed out through the faeces. However, they remained compressed together into a hardened faecal matter and stuck in the intestines, obstructing the free flow of food through the intestines. These compacted faecal matter would rot and rot out the intestines, causing infections and leaky gut, a condition in which the contents of the intestines leaked into the abdominal space, causing further rots and infections.
He also saw swollen and distended (bloated due to pressure from the inside), poorly functioning colons attributed to lack of dietary fibre and poor digestive health (Kellogg, 1910). These occurred because the food gets stuck in the colon owing to the absence of fibre in the diet, causing the food to rot and produce gases, which stretches the colon under intense pressure. If the gases are not released as fart (gas through the anus), they can bloat the stomach and burst the intestines, leading to leaky gut syndrome (the contents of the intestines leak into the abdominal cavity.
Kellogg described seeing signs of inflammation (injured, bloody, swollen) and infection, linked to poor diet and lifestyle choices (Kellogg, 1910). Finally, he saw layers of mucoid plaque (mucus and undigested faeces that has been pressed together into a hardened mass) lining the intestines, attributed to toxin buildup and undigested food particles (Kellogg, 1910).
Several years after Dr. J. H. Kellogg made his discoveries, modern surgeons have come to see the same distortions in the intestines of most people, attributed to our poor diet and implicated in most of our current mental and physical health conditions. In almost all cases, the state of the intestines was a reflection of the health of the person. Generally, healthy intestines are pink and glistening with smooth, regular folds. In contrast, unhealthy intestines may exhibit the conditions described below.
Inflammation: Reddened, swollen sections indicating conditions like Crohn’s disease or ulcerative colitis (Baumgart & Sandborn, 2012). Inflammatory bowel diseases (IBD) are associated with cognitive impairment, possibly due to systemic inflammation affecting brain function (Berrill et al., 2013). Inflammation can interfere with nutrient absorption, leading to deficiencies and related complications such as anemia and osteoporosis (Lamb et al., 2009). Chronic inflammation increases the risk of colorectal cancer (Eaden et al., 2001) and the stress of managing a lifelong condition can lead to increased rates of depression and anxiety (Graff et al., 2009).
Adhesions: Bands of scar tissue causing organs to stick together, often from previous surgeries or infections (Ten Broek et al., 2013). Adhesions can cause chronic abdominal pain, leading to stress and reduced quality of life (Demco, 2004). Chronic pain can interfere with sleep, contributing to fatigue and mood disorders. Adhesions are a common cause of small bowel obstructions, which can be life-threatening if not treated promptly (Liakakos et al., 2001). In women, adhesions can affect fertility by causing obstructions or damage to the reproductive organs (Tulandi et al., 2009).
Tumors or Polyps: Abnormal growths that could be benign or malignant (Lashner, 2003). The diagnosis of tumors or polyps can cause significant anxiety and fear of cancer (Ashiq et al., 2011) and the need for ongoing monitoring and potential surgeries can contribute to long-term emotional distress. Polyps can develop into colorectal cancer if not detected and removed early (Levin et al., 2008). Large polyps or tumors can cause bleeding, leading to iron-deficiency anemia.
Blockages refer to obstructions caused by foreign objects, impacted stool, or twisting of the intestines (volvulus) (Vargas et al., 2008). The sudden and severe pain associated with blockages can cause acute stress and anxiety (Walker et al., 2008) while recurring blockages can lead to chronic worry about future episodes. Prolonged blockages can lead to decreased blood flow (ischemia) and necrosis of the bowel tissue, requiring emergency surgery (Schanzer et al., 1985). Blockages can lead to bowel perforation, causing infections and potentially life-threatening sepsis (Navez et al., 2011).
Diverticula are small pouches in the intestinal walls, potentially leading to diverticulitis if inflamed or infected (Stollman & Raskin, 2004). Diverticulitis, or inflammation of diverticula, can cause chronic pain, impacting mental well-being (Meyer et al., 2015). Patients may experience anxiety about potential flare-ups and complications. If a diverticulum perforates, it can lead to peritonitis, a serious abdominal infection (Stollman & Raskin, 2004). Diverticulitis can lead to fistulas and abscesses, which may require surgical intervention (Weizman & Nguyen, 2011).
Infections: Areas of pus or abscesses indicating bacterial infections (Ramakrishna, 2003). Chronic infections and associated symptoms can contribute to depression (Kurina et al., 2001). Ongoing infections can cause fatigue and cognitive problems, impacting daily functioning. Intestinal infections can lead to systemic inflammation, increasing the risk of other inflammatory conditions (Ramakrishna, 2003). Infections can impair nutrient absorption, leading to deficiencies and associated health issues.
Necrosis: Dead tissue from lack of blood supply, seen in severe bowel ischemia cases (Schanzer et al., 1985).
Perforations: Holes in the intestinal walls leading to leakage of intestinal contents and causing peritonitis (Navez et al., 2011).
The images and descriptions show us what has been observed by medical surgeons in the bodies of other people. If we could get a peep (look) into our intestines and see their nature, formation, appearance, and health, we would immediately become so stunned and disgusted that we will reconsider everything we eat before opening our mouths. You may ask, what causes these intestinal problems? They are caused by our diet and the things we put into our mouths.
How does food affect our brain function and mood?
The central nervous system (CNS) and the gut are intricately connected through a complex network known as the gut-brain axis. This bidirectional communication system involves multiple pathways, including neural, hormonal, and immune mechanisms, allowing the brain and gut to influence each other’s function and health. The vagus nerve is a critical component of the parasympathetic nervous system and serves as the primary neural pathway connecting the brain and gut. It facilitates communication between the gut and brain by transmitting sensory information from the gut to the brain and sending motor commands from the brain to the gut. The food we eat therefore can stimulate the vagus nerve, which then influences our mood and stress levels, indicating its role in emotional regulation (Breit et al., 2018).
Some hormones are produced in the gut, including serotonin, ghrelin, and peptide YY, which influence mood and behaviour. Approximately 90% of the body’s serotonin, a neurotransmitter associated with mood regulation, is produced in the gut (Yano et al., 2015). Gut hormones play a crucial role in appetite regulation, mood, and cognitive functions by signaling the brain about the state of the gut and influencing brain activity (Fetissov et al., 2010). Therefore, the kind of food you eat can determine your mood and behaviour.
There is also a strong association between your food and your immune system and your ability to fight off diseases. There is an immune structure in your gut called Gut-Associated Lymphoid Tissue (GALT), which is located in the gut that monitors and responds to pathogens. It communicates with the CNS (brain) through cytokines and other signaling molecules to modulate immune responses and inflammation. Chronic inflammation in the gut can lead to systemic inflammation, which has been linked to mood disorders such as depression and anxiety (Dinan & Cryan, 2017) and inability to fight off several diseases.
Within the gut are important microbes with good health benefits. The gut microbiota consists of trillions of microorganisms, including bacteria, viruses, and fungi, that reside in the digestive tract. These microorganisms produce neurotransmitters (brain chemicals) and metabolites that can influence brain function and behavior (Cryan & Dinan, 2012). Dysbiosis, or an imbalance in gut microbiota, has been associated with various mental health conditions, including depression, anxiety, and autism spectrum disorders (Clarke et al., 2013). Stress can alter gut microbiota composition and increase intestinal permeability, leading to a “leaky gut.” This, in turn, can trigger systemic inflammation and affect brain function (Kelly et al., 2015).
Chronic stress is associated with gastrointestinal disorders like irritable bowel syndrome (IBS), which can exacerbate mental health issues (Mayer, 2011). Inflammation and altered gut microbiota can affect the production of neurotransmitters like serotonin, contributing to depressive symptoms (O’Mahony et al., 2015). Patients with depression often report gastrointestinal symptoms, highlighting the interconnectedness of gut and mental health.
A diet rich in fiber, fermented foods, and low in processed foods can support a healthy gut microbiota and improve mental well-being (Jacka et al., 2017). Stress management techniques, regular exercise, and adequate sleep are crucial for maintaining both gut and mental health.
Intestines with areas of infection, with visible pus or abscesses indicating bacterial infections. The intestines have sections that look inflamed with pus-filled abscesses, suggesting the presence of an infection.
Effects of specific foods
The food we consume has a profound impact on the health and structure of our intestines. A balanced diet rich in fiber, probiotics, and prebiotics promotes a healthy gut, while poor dietary choices can lead to a variety of intestinal issues.
Dietary fibre from fruits, vegetables, whole grains, and legumes is essential for maintaining the integrity of the intestinal lining and supporting a healthy gut microbiome. It helps prevent constipation and reduces the risk of diverticular disease by promoting regular bowel movements (Slavin, 2008). The fiber acts as a broom, sweeping the walls of the intestines of all left-over food, and soaking them like a sponge for expulsion through the faeces.
Probiotics, which are found mainly in yoghurt, kefir, sauerkraut, kimchi, and other fermented foods, are beneficial bacteria that enhance the balance of gut microbiota, boost immune function, and protect against pathogens (Sanders, 2011). These beneficial bacteria can help restore gut microbiota balance and have been shown to reduce symptoms of depression and anxiety (Messaoudi et al., 2011).
Prebiotics are non-digestible fibres that serve as food for probiotics, promoting the growth and activity of beneficial bacteria (Gibson et al., 2017). They are found in garlic, onions, leeks, asparagus, bananas. They feed beneficial gut bacteria can also positively impact mood and cognitive function (Schmidt et al., 2015)
High-fat diets, usually found in processed foods, fried foods, eggs, dairy, fatty meats, and animal foods in general, can lead to inflammation, alter gut microbiota, and increase intestinal permeability (leaky gut), contributing to gastrointestinal disorders and systemic inflammation (Cani et al., 2008).
Sugar and processed foods, especially found in sugary snacks, soft drinks, and processed snacks, disrupt gut bacteria balance, promote harmful bacteria growth, and lead to inflammation and compromised intestinal lining (Brown et al., 2012).
Proteins. Adequate protein intake is crucial for repairing and regenerating intestinal cells. However, red and processed meat consumption has been linked to an increased risk of colorectal cancer (Chan et al., 2011). Hence protein from plant sources such as soya beans and other legumes, nuts, and seeds are preferable.
Hydration. Proper hydration maintains the mucosal lining of the intestines, facilitating smooth digestion and nutrient absorption (Popkin et al., 2010). Hydration is obtainable through water, herbal teas, hydrating fruits and vegetables.
Antioxidants and Anti-Inflammatory Foods. These foods reduce inflammation, protect the intestinal lining, and support overall gut health (Calder, 2010). They include berries, leafy greens, nuts, seeds, olive oil.
Alcohol and caffeine, obtained from alcoholic beverages, coffee, and energy drinks intake can irritate the intestinal lining, disrupt gut microbiota, and cause digestive issues such as acid reflux, gastritis, and leaky gut syndrome (Bode & Bode, 2003).
Food Sensitivities and Allergies. Food sensitivities and allergies cause inflammation, damage the intestinal lining, and lead to conditions such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) (Bischoff et al., 2014). Allergies are commonly caused by gluten (in celiac disease), dairy (in lactose intolerance), certain nuts, and other allergens.
Evidently, the health of our intestines is significantly influenced by our diet. Abnormal intestinal conditions have profound effects not only on gastrointestinal health but also on mental health and the development of other diseases. The gut and brain are closely linked through the gut-brain axis, involving neural, hormonal, and immune pathways. This complex communication system means that gut health can significantly affect mental capacity and health. Maintaining a balanced diet rich in fiber, probiotics, and prebiotics while limiting high-fat, sugary, and processed foods is crucial for optimal intestinal health. Understanding what surgeons observe during intestinal surgeries and insights from historical figures like Dr. Kellogg can further emphasize the importance of dietary choices in maintaining gut health. Yet, the question remains, in spite of all these findings, do you care?
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