Lactose Intolerance: Common Misunderstandings

Lactose intolerance primarily refers to a syndrome having different symptoms upon the consumption of foods containing lactose. It is one of the most common form of food intolerance and occurs when lactase activity is reduced in the brush border of the small bowel mucosa. Individuals may be lactose intolerant to varying degrees, depending on the severity of these symptoms. When lactose is not digested, it can be fermented by gut microbiota leading to symptoms of lactose intolerance that include abdominal pain, bloating, flatulence, and diarrhea with a considerable intraindividual and interindividual variability in the severity of clinical manifestations. These gastrointestinal symptoms could be similar to cow's milk allergy and could be wrongly labeled as symptoms of "milk allergy." There are important differences between lactose intolerance and cow's milk allergy; therefore, a better knowledge of these differences could limit misunderstandings in the diagnostic approach and in the management of these conditions

Gut Microbiota as Potential Therapeutic Target for the Treatment of Cow’s Milk Allergy.

Cow's milk allergy (CMA) continues to be a growing health concern for infants living in Western countries. The long-term prognosis for the majority of affected infants is good, with about 80% naturally acquiring tolerance by the age of four years. However, recent studies suggest that the natural history of CMA is changing, with an increasing persistence until later ages. The pathogenesis of CMA, as well as oral tolerance, is complex and not completely known, although numerous studies implicate gut-associated immunity and enteric microflora, and it has been suggested that an altered composition of intestinal microflora results in an unbalanced local and systemic immune response to food allergens. In addition, there are qualitative and quantitative differences in the composition of gut microbiota between patients affected by CMA and healthy infants. These findings prompt the concept that specific beneficial bacteria from the human intestinal microflora, designated probiotics, could restore intestinal homeostasis and prevent or alleviate allergy, at least in part by interacting with the intestinal immune cells. The aim of this paper is to review what is currently known about the use of probiotics as dietary supplements in CMA

The role of the commensal microbiota in the regulation of tolerance to dietary allergens.

In this report we review the evidence that environmental stimuli that perturb naturally selected host-microbe interactions are driving the increasing prevalence of food allergy and examine the mechanisms by which commensal bacteria regulate tolerance to dietary allergens. Recent findings Antibiotic use and the consumption of a high fat/low fiber diet have a major, and rapid, impact on gut bacterial populations with long-term consequences for both overall microbial community structure and the regulation of host immunity. Recent work emphasizes the role of mucosa-associated commensal bacteria in eliciting a barrier protective response critical to preventing allergic sensitization to food. Murine model studies are informing the development of novel live biotherapeutic approaches as an adjunctive therapy to enhance antigen specific oral desensitization and promote lasting tolerance in patients with food allergy. Summary Strategies based on modulating the composition and/or functionality of the gut microbiome hold promise for the treatment of food allergy

Excretion of Dietary Cow's Milk Derived Peptides Into Breast Milk

Nanoflow-HPLC-tandem mass spectrometry (MS/MS) was used to analyze the peptide fraction of breast milk samples collected from a single non-atopic donor on different days (10 samples) after receiving an oral load of cow's milk (by drinking 200 mL of bovine milk). In addition, breast milk was sampled from the same lactating mother over a 6-h period at five time points after drinking cow's milk. We aimed to trace the intra-individual variability and to define a time profile of the excretion of dietary peptides into breast milk. Overall, 21 peptides exclusively originating from both bovine caseins and whey proteins with no match within the human milk proteome were identified in the breast milk samples. These peptides were missing in the breast milk obtained from the mother after a prolonged milk- and dairy-free diet (three samples). The time course of cow's milk-derived β-Lg f(125–135) and β-casein f(81–92) in breast milk was determined from the MS ion intensity of the peptide signals. No intact cow's milk gene products were detected by HPLC-MS/MS analysis and Western blotting with anti-β-Lg antibody, but dot-blot analysis confirmed the occurrence of β-Lg fragments in the enriched peptide fraction of breast milk. These data suggest shifting the analytical perspective for the detection of dietary food allergens in breast milk from intact proteins to digested peptide fragments. The possible sensitization and elicitation potential or the tolerogenic properties of such low amounts of dietary peptides for the breastfed newborns remain to be explored