During the 13th Probiotics, prebiotics and new foods congress, held last September in Rome, Microbiomepost sat down with professor Alessio Fasano, pediatric gastroenterologist and researcher at Harvard Medical School.

Fasano reflected on how far microbiome science has evolved — from merely descriptive observations to mechanistic insights that are finally paving the way for clinical application. Thirteen years ago, he notes, most microbiome studies lacked therapeutic direction. Today, technological advances and a deeper understanding of host–microbe communication have brought the field to a critical inflection point.

Fasano’s keynote revolved around three core themes. First, the microbiome as both a target and driver of nutrition: while diet shapes microbial composition daily, emerging evidence suggests that microbes also influence appetite and eating behavior via hormonal signaling — a dynamic particularly relevant in the context of obesity. Second, he emphasized the first 1,000 days of life as a decisive window in which the microbiome programs immune function, determining whether inflammation is used in a protective or pathological way. Disruption during this phase — through C-sections, antibiotic overuse or Westernized feeding — may accelerate autoimmune, metabolic or neurodevelopmental disorders.

Finally, Fasano addressed the challenge of misinformation in microbiome science, warning that the explosion of publications — many of questionable rigor — risks blurring the line between evidence and hype. In a debate with a science journalist, he called for a balance between engaging communication and scientific accuracy, particularly in an era where public health issues like vaccination are easily politicized.

For Fasano, the message is clear: our genetic predisposition is not our destiny — how we feed and protect our microbiome determines the clinical outcome.