Writing Exercise #4

1. Alterations to diet, or general poor diet

Each strain of bacteria either thrives or struggles to live in different, varying environments. Acidophilic bacteria prefer to live in more acidic environments, Neutrophilic bacteria thrive in environments with pH ranges close to neutral (pH of 7), and Alkaliphiles preferentially live in basic environments. Additionally, other bacteria thrive or are killed off by different nutrients, foods, and substances. One’s diet can have a large impact on the environment in their gut. Some dietary/medication related examples:

i.Highly Acidic Diet:
Consumption of acidic foods and drinks such as Coffee, Alcohol, Dairy Products, Tree Nuts, Tomato Sauce, Soda and even carbonated water are all common things we eat that are acidic, some being so acidic that they have a pH as low as 3. By changing the over the acidity of the one’s gut, the microbes which can and will populate the gut is altered.

ii.Overuse of GERD medication(i.e. Antacids, Proton Pump Inhibits, H₂Blockers, etc.)
Many people are affected by GERD, and many take medication (both over-the-counter, and prescription) to treat the symptoms of GERD like acid-reflux. Just as the acidity of one’s diet can impact their gut pH, medications made to directly impact gut pH either directly or indirectly. Antacids like tums contain some compound which acts as a buffer to target and neutralizes stomach acid directly. H₂ Receptor Blockers (H2RBs), and Proton Pump Inhibitors (PPIs) act indirectly by aiming to decrease the overall amount of stomach acid produced. Some studies have shown that overuse of acid-reducing medication leads to an increased risk of developing C. difficile infections. (1)

iii. Antibiotics/Probiotics
Antibiotics are another medication which can have an impact on the overall gut microflora. By killing different bacteria depending on the antibiotics and the mechanisms of its actions, different bacteria have extra space and nutrients to replicate and change the microbial community of one’s gut. (1) Probiotics are the exact opposite of antibiotics and aim to increase the presence of certain bacteria. By introducing new bacteria to one’s gut, little explanation is needed to show how this could impact one’s microbial balance.

iv. Diets High in Sugar

Certain organisms use glucose (table sugar) as a source of energy. A diet high in sugars will provide nutrients for these organisms and could lead to different organisms prospering and creating a microbial imbalance (or dysbiosis). Candida albicans, commonly referred to as ‘yeast,’ is an opportunistic pathogen that is present in nearly 100% of human gut microbiomes. High sugar diets can lead to microbial imbalances and Candida overgrowth. (2)

2. Hygiene

Living or working in environments full of bacteria, (such as garbage men, pre-school teachers, healthcare providers, etc) leads to direct exposure to many foreign bacteria or high concentrations of various microbes. These can alter the diversity, and balance of one’s microbiome. This can be good, or bad for one’s health. By being exposed to new bacteria, one can develop a level of immunity to protect from future infections. However, the exposure can lead to infection, and other illnesses if the bacteria are pathogenic.

i. Animals

Another common source of foreign bacterial exposure is from pets. It is not rare for one to let their pet, or other’s pets, lick their face, hands, and even mouths. Dogs are known to eat just about anything and don’t understand hygiene. Thus, it is expected that these licks could pass on microbes to humans, which could then alter one’s gut microflora.

3. Stress

Chronic stress alters the hormones which are present in the body. These hormones can impact the microbial communities of the gut. Cortisol and Adrenaline are some of the stress-response hormones that increase under times of heavy stress as part of the body’s ‘flight or fight’ response. These hormones increase the rate of production of bile and stomach acid, thus altering the internal environment of the gut. Long-term stress gives the acidophilic bacteria time to out-compete other bacteria and colonize the gut in place of the non-acidophilic bacteria. These bacteria, as well as the increased acidic conditions of the stomachs, can even lead to the development of gastric ulcers.

References:

1. Kwok, C., Arthur, A., Anibueze, C., Singh, S., Cavallazzi, R. and Loke, Y. 2014. Risk of Clostridium difficile Infection With Acid Suppressing Drugs and Antibiotics: Meta-Analysis. Am J Gastroenterol 107:1011-9
2. Martins, N., Ferreira, I., Barros, L., Silva, S. and Henriques, M. 2011 Candidiasis: Predisposing Factors, Prevention, Diagnosis and Alternative Treatment. Mycopathologia 177:223-40.