Babies with food allergies may develop a microbiome imbalance

Children born with food allergies, metabolic deficiencies, and celiac disease need special formulas and diets, excluding part of foods. Is your child one of them? Read on to learn how elimination diets influence the microbiome and how to prevent their harmful effects.

The role of the microbiome in allergenic response

A food allergy is a hypersensitivity to a specific food. Allergologists classify types of food allergies into

IgE-mediated, where a meal with allergenic food stimulates a rapid increase in IgE class antibodies (antibodies connected with fighting parasite infection), which binds with immune cells, causing an allergic reaction.
And non-IgE-mediated, where the immune cells are activated without antibodies, causing many gastrointestinal tract disorders.

Microbes living in the intestine, collectively called gut microbiome, may influence the generation of specific immune cells. They, in turn, replace cells driving IgE-depending allergy reactions.

Diet and microbiome composition

The gut microbiome composition depends on many factors, such as term and mode of birth, antibiotic exposure, or siblings and pets at home.

The most critical factor for gut colonization is a birth event when your baby’s intestine is rapidly flooded with environmental microbes. After birth, your child’s exposure to breast milk or formula and the environment will allow the gut microbiome to reach values comparable with those found in adults.

We know that diet is a major player in shaping infant microbiomes. When your baby reaches six months, they are ready to pass from milk-exclusive feeding to complementary feeding. Microbes residing in your child’s gut use dietary fibers and incompletely digested proteins as a source of energy. So these components impact the microbial composition.

In fermentation, microbes turn dietary fiber into short-chain fatty acids like acetate or butyrate. These short molecules deliver energy to your baby’s colon cells and influence intestinal barrier function, metabolism, immune and nervous systems.

Bifidobacteria influence your child’s immunity

Breast milk contains over 200 human oligosaccharides (HMOs) – complex ingestible sugars. Humans do not digest them, but HMOs serve as food for specific bacteria called bifidobacteria. The lack of bacteria from this family has been associated with autoimmune conditions (Vatanen et al. 2016; Stokholm et al. 2018; Henrick et al. 2019).

Microbiomes of children exclusively fed with formula differ from healthy infants. Due to the lack of HMOs and higher protein content in milk formulas, your baby fed with formula has a lower abundance of Bifidobacterium species, increased Clostridium species, and Enterobacteriaceae like E. coli.

But research suggests infants fed with formula supplemented with HMO had similar levels of bifidobacteria to babies fed exclusively with breast.

Observe your baby. Children fed with special formula may need support in maintaining a healthy microbiome.

Role of Lactobacillus rhamnosus GG in the development of tolerance to cow’s milk protein

Allergy to cow’s milk (CMA) is children’s most common food allergy. Pediatricians and gastroenterologists recommend extensively hydrolyzed formulas for treating infants with confirmed CMA allergies. In hydrolyzed formulas, cow protein in milk is cut into smaller pieces to impede recognition by immune cells. In severe cases, physicians prescribe amino-acid-based formulas. They are composed of minimal protein-building units like bricks building a house.

Studies showed that bacterium belonging to Bacilli – Lactobacillus rhamnosus GG might stimulate CMA antigen tolerance development.

Some producers supplement formulas with those bacteria, but one must remember that lactose is the primary energy source for Lactobacilli. Thus formulas should ideally include lactose.

Take care of diversity in your baby’s diet

When children with food allergies grow up, their diet becomes more affluent, but in some cases, they still need to avoid allergenic foods. This may, but not necessarily, lead to microbiome imbalance (Di Profio et al. 2022). Why?

Scientists studied the microbiomes of toddlers feeding with traditional Mediterranean, Nordic, Japanese, or Atlantic diets. What distinguishes these eating habits is large amounts of non-processed foods high in fiber and antioxidants.

Robust literature data (Di Profio et al. 2022; Krznarić et al. 2021; Kushida et al. 2019; Vaz-Velho, Pinheiro, and Rodrigues 2016) demonstrate that these traditional diets lead to higher microbial diversity and promote a positive balance between the main phyla: Firmicutes and Bacterioidetes. They also improve the immune system and liver function.

Like toddlers on the Western diet (high in sugar, fats, and processed foods and low in fresh vegetables), children, especially with many food allergies, may not eat enough prebiotics. This eating style impairs the microbiome balance severely, reducing microbial richness. The other impact may include neural system development and fat storage disruptions, leading to obesity.

Five steps to a healthy tummy

The interplay between beneficial bacteria and immunity is proven. Support your child’s immunity development with these steps:

Breastfeed your baby if you can,
use formula supplemented with lactose, HMOs, and desiccated Bifidobacteria, Lactobacilli, or supplement bacteria by yourself with special infant droplets or powders,
introduce your toddler fermented foods according to the complementary food calendar (Tuck 2013),
avoid sugar and high-fat processed foods and replace them with fruits, vegetables, fish,
remember to contact a pediatrician or dietetics who can point foods suitable to your child with an allergy, supporting healthy microbiome development.

Martyna Piotrowska

The article is based on the paper published in Nutrients: Nutrients | Free Full-Text | Special Diets in Infants and Children and Impact on Gut Microbiome | HTML (mdpi.com)