A new study published in PLOS Global Public Health contributes to the growing evidence that nutrition should be treated as a core part of tuberculosis care - not an afterthought.
The research, conducted in India, explores how the body's metabolism shifts throughout treatment for TB and suggests that malnutrition could directly affect how well patients respond to therapy.
The findings, from a team at the Cornell Joan Klein Jacobs Center for Precision Nutrition and Health in the College of Human Ecology, led by postdoctoral fellow Catherine Kagemann, arrive just as the World Health Organization released sweeping new guidelines in October. The guidelines urge countries to integrate nutritional assessment and support into all tuberculosis programs, a major shift in global TB policy.
"Even after successful TB treatment, we found that there is still a metabolic scar in these patients," Kagemann said. "This prompted us to want to try nutrition interventions in future studies."
The research team analyzed the metabolites, the small molecules that play key roles in metabolism, of people with mild and severe pulmonary TB across six months of treatment. They found distinct metabolic patterns that changed as therapy progressed, offering new clues into how infection severity and treatment alter the body's physiological systems.
"When modern TB treatments came on board in the 1960s, they were so successful that many programs dropped nutrition from their agenda," said Dr. Saurabh Mehta, corresponding author and director of the Jacobs center. "But TB destroys your lifetime of built-up resources. So while the treatment kills the bacteria, the question is how do we restore the whole system so people aren't prone to relapse or getting other metabolic diseases."
For decades, tuberculosis treatment has centered on antibiotic regimens designed to kill the bacterium Mycobacterium tuberculosis. But the pathogen is notorious for manipulating its host's metabolism to survive, often leaving patients weak and nutritionally depleted.
Malnutrition is both a cause and a consequence of TB, according to Kagemann. Undernourished people are more likely to contract the disease, and TB infection itself can cause severe wasting, a vicious cycle long recognized but poorly understood at the molecular level. The new research takes aim at that gap.
By incorporating both chest X-ray imaging and sputum smear tests - the latter a measure of bacterial burden - the study offered a more complete picture of how the body's metabolism shifts with disease severity. Patients with higher bacterial loads showed distinct metabolic disruptions, potentially pointing to biomarkers that could guide future treatment or nutrition interventions.
The WHO's updated guidelines on tuberculosis and undernutrition, released Oct. 8. Those recommendations emphasize that nutrition screening and support should become a standard part of TB diagnosis and treatment - marking a shift toward more holistic care.
The WHO estimates that 8.2 million people were diagnosed with TB in 2023, making it once again the world's leading infectious killer. In many low- and middle-income countries, food insecurity and TB remain deeply intertwined. In the U.S., tuberculosis cases reached a 13-year high in 2024.
The pilot study conducted in India provides early but valuable evidence that metabolic insights could help tailor treatment for persons with tuberculosis based on nutritional and disease status, an approach long missing from TB programs, Kagemann said.
"In a different study with a larger cohort in China, they found the same metabolic scarring at the end of the anti-TB treatment," she said. "Our next step is to see if sufficient food of any kind, just a general balanced diet, improves outcomes after TB treatment, or whether a more targeted precision nutrition approach is more effective."
If expanded, this work could inform not only how doctors monitor treatment progress but also how governments structure nutritional support in TB care, potentially saving lives and improving recovery rates. This builds upon recent work by Mehta and his colleagues - for example, an editorial in the Lancet advocating for food support for persons with TB disease and their household contacts and a paper in the Lancet Global Health laying out a roadmap for nutritional support for patients with TB disease.
"We have been fervently searching for a new vaccine, more effective drugs and host-directed therapies to prevent TB deaths and help patients reclaim their lives," said Dr. Pranay Sinha, an infectious diseases physician at Boston Medical Center and faculty fellow at the Jacobs Center who led the development of the roadmap. "But even as we search for remedies in sophisticated labs, we must not ignore those already available in the local grocery store. The challenge now is to implement nutritional interventions with precision and equity.
This study, conducted using samples from RePORT India, a decade-long Indo-US collaborative tuberculosis program funded by USAID, tracks how the body's metabolic profile changes during anti-TB treatment, revealing distinct patterns in individuals with mild versus severe tuberculosis.
"These findings provide a window into the biological processes underlying disease severity and treatment response, paving the way for more targeted and effective approaches to TB care," said Senbagavalli Prakash Babu, the principal investigator of the study supported by the Partnerships for Enhanced Engagement in Research (PEER), a USAID-funded program.
"Curing the disease or infection is not enough," Mehta said. "We also have to reconstitute and rehabilitate the person."
