While walking past the dairy aisle in your grocery store, you must have noticed that this aisle has been mostly taken by the fermented dairy product, yogurt, jam-packed with beneficial bacteria called probiotics. Why are these probiotics gaining popularity? Why is it so crucial to use probiotics and keep your gut microbiome healthy? Many of these queries have already been sought. Still, most people are unaware of the importance of gut health and its microbiota.
The gut microbiome that used to be a “forgotten organ” a few decades back, has rapidly gained momentum in recent years. The microbes that make up the microbiome are essential not only for our gut, immune, and heart health but also actively synthesize the major neuroactive brain chemical, manipulating our mind and behavior. Knowing which factors are harmful to your tiny partners-in-defense is thus of paramount importance.
1. Poor diet
Lifestyle factors play a major part in shaping the composition and activity of the teeming microbial populations in your gut.
Diet, in particular, macronutrients modify the health of bugs inhabiting our body, and these, in turn, impact our general health.
The current Western diet is sabotaging the microbiome health.  Today, people consume more red meat, processed and fried foods, high-fat dairy products, potatoes and similar high-carb foods, bottled juices chock full of high-fructose corn syrup, and other foods with added sugars.
The intake of additional sources of saturated (unhealthy) fats as found in butter and cheese is also at its peak. These dietary saturated fats may boost the amount of inflammation-promoting gut microbes by inciting the formation of compounds called bile acids. 
On the other hand, our diet lacks microbiome-friendly foods like:
- Quality fermented foods (yogurt, kefir, and Kombucha)
- Green leafy vegetables and fiber and antioxidant-rich fruits
- Garlic, onions, Jerusalem artichoke, leeks, asparagus, chicory root, and many other fruits and vegetables. These are rich in prebiotic fiber, a unique type of indigestible dietary fiber that fuels the beneficial gut bacteria and allows them to thrive
2. Sitting more and moving less
A lack of exercise alone is altering our gut microbiome in a way that lowers the production of short-chain fatty acids (SCFAs). These SCFAs are beneficial compounds produced in lean and fit people in response to the fermentation of dietary fiber by the friendly bacteria in your colon.  They have a variety of benefits, including but not limited to:
- Nutrient supply
- Gut barrier protection
- Suppression of abnormal cell growth
- Reduction in free radical damage
- Regulation of gut motility
- Gene regulation
In contrast, where a sedentary lifestyle leads to chronic illnesses like heart disease, diabetes, cancer, and metabolic syndrome, it also interferes with all the afore-listed protective functions by wreaking havoc on the gut microbiome. 
3. Antibiotic use
We know that using antibiotics can shift the composition of the intestinal flora from good to bad. A certain class of antibiotics even triggers the overgrowth of a dangerous bug like Clostridium difficile that causes acute inflammation of your colon and life-threatening diarrhea. 
Regular use of probiotics can boost your immunity and prevent you from contracting infections. However, if you do catch any infection, be sure to ask your doctor about supplementing probiotics along with the course of antibiotics to keep your tiny gut friends happy.
Smoking has a hefty impact on the gut microbiota composition. The changes in the bacterial community secondary to smoking as well as the toxic particles in the smoke can potentially lead to Crohn’s disease. Smoking induces free radical damage, disrupts the intestinal tight junctions, and alters the acid-base balance of your body. Altogether, these changes put your gut microbiome health at risk. 
5. Psychological stress
Stress influences gut functions via the gut-brain axis, which can modify gut microbiota profiles, for instance reducing the numbers of potentially beneficial Lactobacillus bacteria. The ensuing changes in the gut microbial makeup can then trigger IBS and mood disorders due to the gut-brain link. 
Traveling to overseas places also influences gut health and alters the gut bacterial composition. It puts you at risk of contracting and spreading infectious diseases, including diarrhea. If such infections go unnoticed for a long time, GI problems like IBS ensue. 
- Zinöcker MK, Lindseth IA. The Western Diet-Microbiome-Host Interaction and Its Role in Metabolic Disease. Nutrients. 2018;10(3):365. Published 2018 Mar 17. doi:10.3390/nu10030365.
- Devkota S, Wang Y, Musch MW, et al. Dietary-fat-induced taurocholic acid promotes pathobiont expansion and colitis in Il10-/- mice. Nature. 2012;487(7405):104-8.
- Monda V, Villano I, Messina A, et al. Exercise Modifies the Gut Microbiota with Positive Health Effects. Oxid Med Cell Longev. 2017;2017:3831972.
- Cerdá B, Pérez M, Pérez-Santiago JD, Tornero-Aguilera JF, González-Soltero R, Larrosa M. Gut Microbiota Modification: Another Piece in the Puzzle of the Benefits of Physical Exercise in Health?. Front Physiol. 2016;7:51. Published 2016 Feb 18. doi:10.3389/fphys.2016.00051.
- Langdon A, Crook N, Dantas G. The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation. Genome Med. 2016;8(1):39. Published 2016 Apr 13. doi:10.1186/s13073-016-0294-z.
- Savin Z, Kivity S, Yonath H, Yehuda S. Smoking and the intestinal microbiome. Arch Microbiol. 2018 Jul;200(5):677-684. doi: 10.1007/s00203-018-1506-2.
- Conlon MA, Bird AR. The impact of diet and lifestyle on gut microbiota and human health. Nutrients. 2014;7(1):17-44. Published 2014 Dec 24. doi:10.3390/nu7010017.