Question

What are the negative effects of probiotics on our body? (Please give a detail explanation on this and also references used, Wikipedia is not acceptable, thanks)

Answer 1

Probiotics are useful strains of living bacteria and yeast that provide health benefits and also helps maintain the gut biota when taken in the right quantity. Probiotics help people with diarrhea, inflamatory bowel diseases and irritable bowel syndrome. Generally, probiotics have positive effect on the body but individuals with comprimised immune system, children who are sick and people who have undergone a surgery need to be weary as it has been shown to induce severe side effects leading to dangerous infections (MDLinx, 2019, WebMD and Harvard Health Publishing, Harvard Medical School). Transfer of antibiotic resistence gene from the probiotic bacteria to other bacteria in the gut is another undesirable and harmful side effect that can happen due to consumption of probiotics (National Center for Complementary and Intergative Health). They can even pass on the harmful strains that can later on cause seroius infections in the person.  Researchers have found that probiotics can evolve to become antibiotic resistant and showed that they are able to compete better with the gut microbes and predominate the gut after removing them (MDLinx). The milder side effects that people face are bloating and constipation. The amines present in fermented probiotics can trigger headaches and increase levels of histamine in the body, therefore people with histamine intolerence need to be careful of the probiotics they take (Healthline). Some probiotics contain bacteria that have not been listed and these are contaminants which can cause serious health risks (National Center for Complementary and Intergrative Health).  

Therefore, generally probiotics do not have any serious negaitve effects but as mentioned above there are certain things that one might need to be careful before taking them.

References -

1. Benefits and drawbacks of probiotics: How much is too much? by Samar Mahmoud, for MDLinx | April 08, 2019 - https://www.mdlinx.com/internal-medicine/article/3618

2. Harvard Health Letter, Should you take probiotics? - https://www.health.harvard.edu/staying-healthy/should-you-take-probiotics

3. US Department of Health and Human Services, Probiotics: What you need to know, National Center for Complementary and Integrative Health - https://www.nccih.nih.gov/health/probiotics-what-you-need-to-know

4. https://my.clevelandclinic.org/health/articles/14598-probiotics

5. Healthline, 5 Possible side effects of Probiotics - https://www.healthline.com/nutrition/probiotics-side-effects

6. https://www.medicalnewstoday.com/articles/323821

7. WebMD, Risk and Benefits of Probiotics - https://www.webmd.com/digestive-disorders/probiotics-risks-benefits#1