As city clinics report a 30% rise in infections, experts warn that the 40°C heatwave and high humidity are rewriting one’s gut microbiome.
Kolkata, April 24, 2026: The city of Kolkata is struggling with an intense and oppressive summer; many days are seeing temperatures climb above 40°C with extreme humidity levels typical of the Gangetic plain. Due to this severe weather, there has been a sharp rise in gastrointestinal infections and acidity amongst the residents.
Hospitals in Kolkata have seen a huge rise in seasonal kinds of gastric problems. Diagnostic facilities are reporting an increase of 20-30% in patients diagnosed with acute diarrhoeal diseases (ADD), severe acidity conditions, and food poisoning. This increase is primarily due to the rapid acceleration of bacterial growth within food and water as a result of the sweltering heat. Consequently, a new heatwave alert was issued for West Bengal recently, warning citizens of “markedly above normal” temperatures.
Doctors have found that while increased temperatures cause dehydration (leading to constipation and acid reflux), the high humidity of Kolkata creates optimal conditions for pathogens like Salmonella and H. pylori to flourish. Common clinical presentations include Gastroenteritis/ADD, frequently seen among children and the elderly, mainly due to the consumption of uncovered street food and the rapid spoilage of perishables in the damp heat.
“Due to the high fluctuation in temperature in the summers in Kolkata, what we are currently seeing is an increase not only in gastrointestinal infections but a change in the nature and the causative agents as well. The food spoils much faster in such weather, with bacteria growing faster. Hence any mild contamination of the food or water may cause infections. On the other hand, dehydration affects the body’s ability to digest, resulting in diarrhoea or constipation”, says Dr.Indraneel Saha , consultant physician and specialist in gastroenterology and therapeutic endoscopy , Neuberg Pulse Diagnostics
Heat-induced Gastritis has also seen a dramatic increase, especially among those working in the city’s commercial hubs, resulting from excessive caffeine intake and irregular meal hours. Additionally, there is an increasing number of patients reporting piles and anal fissures as a direct result of summer-related dehydration and low fiber intake during travel.
Dr. Saha continues, “It is vital to realize that some gastrointestinal problems in the summers may look minor and harmless in the initial stage; however, they might actually be symptoms of some infection such as typhoid, bacterial or parasitic. Therefore, testing for these diseases early on becomes very important.”
The issue of self-medication remains rampant, leading to increasing antibiotic resistance. “In these situations, an appropriate diagnosis method must be used. Some of the most commonly prescribed laboratory tests during this time frame are CBC, CRP, stool routine and microscopy, stool culture and sensitivity, and serum electrolyte analysis. This will determine the underlying problem and ensure that proper treatment can be provided”, he concludes.
Experts warn that the recent India Gut Health Report 2026 indicates 82% of Indians have acidity but few seek proper diagnostic evaluation. In times of severe weather, it’s essential to take a “Gut-First” approach: drink ORS or buttermilk, avoid roadside raw salads, and eat hot foods instead of cold foods.
