The hidden language of the gut: a milk protein may help maintain balance

We share this report from Heraldo de Aragón about a study that indicates that lactoferrin regulates serotonin production.

A protein found in milk may play an unexpected role in gut health. It's called lactoferrin, and according to a study by the University of Zaragoza and the Agri-food Institute of AragonIt can help the gut maintain its balance by regulating the production of Serotonin, a key molecule that connects digestion, immunity, and emotionsTheir discovery opens new avenues for understanding how certain foods can influence our health beyond nutrition.

The control center

When we think about serotonin, we usually imagine neurons and emotions. But Almost all of the body's serotonin, around 90%, is produced in the gutwhere it modulates motility, secretion, and even pain sensitivity. This system, known as the intestinal serotonergic system, is a true control center of the digestive tract, and when it loses control, inflammatory bowel diseases appear. This is where lactoferrin, a natural milk protein, comes into play.

A team from the University of Zaragoza has discovered that this molecule can help the gut maintain balance, especially in situations of inflammation. In experiments conducted on an experimental model of colitis, lactoferrin was able to reinforce the activity of the serotonin transporter, responsible for keeping serotonin levels under control and reducing signs of inflammation. In other words: Lactoferrin helped the gut to 'turn down' the serotonergic signal when inflammation got out of control. This protein has important biological activities in the development of the newborn and can be isolated from milk for use in special products intended to improve health.

This finding opens new perspectives for understanding how Certain natural components of food can interact with the mechanisms that regulate intestinal health. At a time when the gut-brain axis is increasingly discussed, this story reminds us of something essential: what we eat not only nourishes us, but can also speak to our emotions, through a chemical language shared between the digestive and nervous systems: serotonin.

The publication

• Article 'Protective role of bovine lactoferrin in modulating the intestinal serotonergic system: Implications in intestinal inflammation'.
• The magazine Journal of Nutritional Biochemistry.
• Brands The authors belong to the research group Effect of Technological Food Processing on Digestive and Allergic Pathologies (Alipat), whose principal investigators are Laura Grasa and Lourdes Sánchez, and to the university research institutes IA2 and IIS Aragón. Principal author: Berta Buey. Co-authors: Inés Abad, Andrea Bellés, Marta Castro, Marta Sofía Valero, M. Pilar Arruebo, Laura Grasa, Lourdes Sánchez, Miguel Ángel Plaza, José Emilio Mesonero, and Eva Latorre.
• Open access.

What if the gut had its own emotions?

For years, serotonin was thought to be the exclusive domain of the brain, a molecule associated with pleasure, appetite, and well-being, but whose deficiency is linked to depression and anxiety. However, 90% of it is produced in the gut, manufactured by cells that detect what we eat, what we feel, and even how our gut bacteria behave. In inflammatory bowel disease, that 'serotonin factory' goes out of control.It is released in excess, the lining becomes inflamed, digestion accelerates, pain increases, and mood suffers. The gut then seems to speak its own chemical language, capable of altering both digestion and emotions. What if this emotional rollercoaster that accompanies these illnesses is not only psychological, but a chemical response originating deep within the gut itself?

Can a bacterium change our mood?

It sounds like science fiction, but there is growing evidence that The gut microbiome influences how we think and feel. Some bacteria produce or break down tryptophan, the amino acid from which we make serotonin. Others modulate the immune cells that monitor the intestinal lining and determine whether something is an ally or a threat. 

In inflammatory bowel diseases, this balance is disrupted: bacterial species change, serotonin levels rise, and the immune system overreacts. The result is not only inflammation and pain, but also mood, sleep, and appetite disturbances. Understanding this microbiota-brain connection It could help treat both gut and emotional health from the same perspective.

What do an antidepressant and an anti-inflammatory have in common?

At first glance, not much. One acts on the brain and the other on the gut. But both converge on the same molecule: serotonin. Drugs that increase its availability in the brain (such as SSRI antidepressants) also act outside the central nervous system, especially in the gut, where serotonin regulates motility, secretion, permeability, and the immune response. In fact, Some patients with inflammatory bowel disease treated with antidepressants experience fewer flare-ups, abdominal pain, or digestive anxiety.However, it is still debated whether this is due to a direct effect on intestinal cells or to a reduction in stress and systemic inflammation.

Parallel, New anti-inflammatory therapies seek to block specific serotonin receptors in the gut to modulate inflammation without affecting the brain. Perhaps we are facing a common path where mental and digestive health intersect much more than we imagine.

Source: Heraldo de Aragón