Pollutants altering gut health of India’s wild tigers, warn Hyderabad scientists

Hyderabad-led study has revealed alarming changes in the gut microbiome of India’s wild tigers, linking pollutants and human interference to compromised digestive health. Researchers warn the shifts could affect tiger immunity, fitness, and conservation outcomes across major reserves

Hyderabad: New evidence in a groundbreaking study led by Hyderabad-based scientists has revealed that the majestic Indian wild tiger’s gut health is being compromised by human activity. For over two years, the scientists meticulously analysed the tiger scat (faeces) collected from prominent tiger reserves, which unearthed insights into the big cat’s gut microbiome.

In the study, published in Global Ecology and Conservation (September-November, 2025) journal of Elsevier, that employed advanced DNA analysis techniques, scientists from Hyderabad were able to map the intricate communities of bacteria residing within the tigers’ digestive systems, i.e., their gut microbiome.

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The study, led by G Umapathy of Hyderabad-based Centre for Cellular and Molecular Biology (CCMB), has unequivocally indicated a concerning trend: the gut microbiome in Indian wild tigers is changing.

The researchers, who conducted the two-year study at five major Indian tiger reserves including Corbett (Uttarakhand), Bandhavgardh and Kanha in Madhya Pradesh, Tadoba-Andhari in Maharashtra and Periyar in Kerala, discovered alarming signs that tigers are metabolising substances linked to pollutants and other human-related activities.

The substances linked to pollutants suggests a direct human interference in the tiger’s internal ecosystem, where the very bacteria essential for digestion, immunity, and overall well-being are adapting to a polluted or disturbed environment.

The comprehensive investigation, which involved collecting fresh samples from both the highly protected core zones and the more human-influenced buffer zones at the tiger reserves, aimed to understand how external environmental factors shape the internal microbial world of these big cats.

These findings carry significant implications for the conservation of India’s tiger population, as a healthy gut microbiome is fundamental to an animal’s ability to absorb nutrients, fend off disease, and manage stress.

Human encroachment, tourism, cattle grazing, or other anthropogenic pressures have the potential to alter the delicate internal balance, compromise the long-term health, fitness and reproductive success of tigers.

The Hyderabad scientists’ work indicates urgent need to mitigate human impact within and around tiger reserves, not just for the visible threats, but for the unseen, yet crucial, battle being waged within the tigers themselves.