Gastroenterologist shares 10 ways excess antibiotic use can harm your gut health: From diarrhoea to weight gain risks

Do you frequently take antibiotics without proper medical guidance? You may want to reconsider as the repercussions are extensive.

Antibiotics are prescribed by doctors to fight infections. However, because they are so commonly prescribed, many people take matters into their own hands when they fall sick and start popping these medicines without proper medical advice. This constitutes misuse in many ways. Without correct guidance, their effectiveness is questionable, and more importantly, gut health is also severely affected.

To understand how negatively antibiotic misuse can impact gut health, HT Lifestyle reached out to Dr (Prof.) P. K. Mishra, senior director, surgical, gastroenterology at Max Super Speciality Hospital, Patparganj. He revealed that antibiotics should not be misused. “When antibiotics are used, especially repeatedly or unnecessarily, they can disturb this delicate ecosystem, leading to several health concerns,” he noted.

Why do antibiotics harm gut health?

While antibiotics kill bacteria to fight infection, the gastroenterologist pointed out that they cannot differentiate between harmful and beneficial bacteria. Since good gut health depends on beneficial microbes, this leads to a significant blow to overall gut health.

It creates a gut disturbance, which the surgeon called gut dysbiosis. He elaborated, “Antibiotics eliminate healthy gut bacteria that support digestion, nutrient absorption, and immune function, leading to reduced gut diversity and weakened overall gut health.”

He mentioned several digestion-related problems like: diarrhoea, bloating, weakened immunity, increased risk of infections, and delayed recovery of the gut microbiome.

10 ways antibiotics adversely affect gut bacteria

IBS symptoms include diarrhoea or constipation. (Shutterstock)

There are multiple ways your gut health can suffer from excessive antibiotic use, whether by triggering an imbalance in gut bacteria or impairing nutrient absorption, with the effects going from short-term digestive discomfort to serious long-term health complications.

The gastroenterologist listed out these 10 ways in which gut health is at risk because of your antibiotic usage, which you need to take note of:

1. Decline in protective gut bacteria

• Antibiotics act broadly and cannot selectively target only harmful bacteria.
• In the process, they reduce populations of beneficial gut microbes, lowering microbial diversity and weakening the gut’s natural defence system.

2. Digestive discomfort and bowel disturbances

• Altered gut environment commonly results in diarrhoea, bloating, gas, abdominal cramps, or constipation.
• Antibiotic-associated diarrhoea is among the most frequently reported side effects, particularly in children and elderly patients.

3. Overgrowth of harmful organisms

• With protective bacteria suppressed, harmful microbes can multiply unchecked.
• This raises the risk of infections such as Clostridioides difficile, which may cause severe diarrhoea and inflammation of the colon

4. Compromised immunity

• Large portion of the immune system is regulated by gut bacteria.
• Antibiotic-induced imbalance weakens immune responses, making individuals more prone to infections, allergies, and delayed recovery from illness.

5. Prolonged disruption of gut balance

• While some gut bacteria recover within weeks, others may take months or longer to return.
• Frequent antibiotic use can permanently alter gut composition, increasing vulnerability to digestive disorders.

6. Reduced nutrient absorption

• Beneficial gut microbes assist in the absorption of key nutrients such as B vitamins, vitamin K, iron, and magnesium.
• Disruption of this process may contribute to nutritional deficiencies and fatigue.

7. Inflammation of the gut lining

• Unhealthy gut microbiome can irritate and damage the intestinal lining.
• This triggers inflammation and increases the risk of conditions like irritable bowel syndrome (IBS).

8. Rising antibiotic resistance

• Excessive antibiotic exposure encourages the survival of resistant bacteria in the gut.
• Makes future infections harder to treat and reduces the effectiveness of commonly used medicines.

9. Impact on mental well-being

• Gut–brain connection means changes in gut bacteria can influence mood and emotional health.
• Antibiotic-related gut imbalance may be linked to anxiety, stress, and low mood.

10. Metabolic health issues

• Disturbed gut bacteria may influence metabolism.
• Increases the risk of weight gain, insulin resistance, and metabolic disorders over time.

Dr Mishra reminded that while antibiotics are crucial for treating bacterial infections, their unnecessary or improper use can significantly disrupt gut health. Instead, what is ideal? “Taking antibiotics only when prescribed, adhering to the recommended dosage, and supporting gut recovery through a balanced diet and doctor-advised probiotics can help restore healthy gut bacteria and minimise long-term effects,” he advised.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.