Management of food allergy: vitamins, fatty acids or probiotics?

Comparison of two oral probiotic preparations in a randomized crossover trial highlights a potentially beneficial effect of Lactobacillus paracasei NCC2461 in patients with allergic rhinitis

Background

There is promising but conflicting evidence to recommend the addition of probiotics to foods for prevention and treatment of allergy. Based on previous studies with fermented milk containing Lactobacillus paracasei NCC2461, we aimed to compare the effect of a powder form of the latter probiotic with the effect of a blend of Lactobacillus acidophilus ATCC SD5221 and Bifidobacterium lactis ATCC SD5219 in patients with allergic rhinitis.

Methods

A double-blind, randomized, cross-over study, involving 31 adults with allergic rhinitis to grass pollen, was performed outside the grass pollen season (registration number: NCT01233154). Subjects received each product for 4-weeks in two phases separated by a wash-out period of 6 to 8 weeks. A nasal provocation test was performed before and after each 4-week product intake period, and outcome parameters (objective and subjective clinical symptoms; immune parameters) were measured during and/or 24 hours after the test.

Results

Out of the 31 subject enrolled, 28 completed the study. While no effect was observed on nasal congestion (primary outcome), treatment with NCC2461 significantly decreased nasal pruritus (determined by VAS), and leukocytes in nasal fluid samples, enhanced IL-5, IL-13 and IL-10 production by peripheral blood mononuclear cells in an allergen specific manner and tended to decrease IL-5 secretion in nasal fluid, in contrast to treatment with the blend of L. acidophilus and B. lactis.

Conclusions

Despite short-term consumption, NCC2461 was able to reduce subjective nasal pruritus while not affecting nasal congestion in adults suffering from grass pollen allergic rhinitis. The associated decrease in nasal fluid leukocytes and IL-5 secretion, and the enhanced IL-10 secretion in an allergen specific manner may partly explain the decrease in nasal pruritus. However, somewhat unexpected systemic immune changes were also noted. These data support the study of NCC2461 consumption in a seasonal clinical trial to further demonstrate its potentially beneficial effect.

Randomized controlled trial using vitamins E and D supplementation in atopic dermatitis

BACKGROUND

Atopic dermatitis is a chronically relapsing, highly pruritic and inflammatory skin disease. This study was done to assess the effects of vitamins D and E supplementation on the clinical manifestation of atopic dermatitis.

METHODS

Forty-five atopic dermatitis patients were included in a randomized, double-blind, placebo-controlled trial. They were randomly divided into four groups and treated for 60 days: group P (n = 11), vitamins D and E placebos; group D (n = 12), 1600 IU vitamin D(3) plus vitamin E placebo; group E (n = 11), 600 IU synthetic all-rac-α-tocopherol plus vitamin D placebo; and group DE (n = 11), 1600 IU vitamin D(3) plus 600 IU synthetic all-rac-α-tocopherol. Serum 25(OH) vitamin D and plasma α-tocopherol were determined before and after the trial. The clinical improvement was evaluated with SCORing Atopic Dermatitis (SCORAD). Data were analyzed by analysis of variance (ANOVA) and Kruskal-Wallis tests.

RESULTS

SCORAD was reduced after 60 days in groups D, E and DE by 34.8%, 35.7% and 64.3%, respectively (p = 0.004). Objective SCORAD also showed significant improvement. There was a positive correlation between SCORAD and intensity, objective, subjective and extent (p < 0.001). We found a significant negative association between plasma α-tocopherol and SCORAD, intensity, objective and extent (p = 0.02).

CONCLUSION

This study supports the contributing and beneficial effects of vitamins D and E in the treatment of atopic dermatitis.

The intestinal barrier and its regulation by neuroimmune factors

BACKGROUND

The ability to control uptake across the mucosa and protect from damage of harmful substances from the lumen is defined as intestinal barrier function. A disturbed barrier dysfunction has been described in many human diseases and animal models, for example, inflammatory bowel disease, irritable bowel syndrome, and intestinal hypersensitivity. In most diseases and models, alterations are seen both of the paracellular pathway, via the tight junctions, and of the transcellular routes, via different types of endocytosis. Recent studies of pathogenic mechanisms have demonstrated the important role of neuroimmune interaction with the epithelial cells in the regulation of barrier function. Neural impulses from extrinsic vagal and/or sympathetic efferent fibers or intrinsic enteric nerves influence mucosal barrier function via direct effects on epithelial cells or via interaction with immune cells. For example, by nerve-mediated activation by corticotropin-releasing hormone or cholinergic pathways, mucosal mast cells release a range of mediators with effects on transcellular, and/or paracellular permeability (for example, tryptase, TNF-alpha, nerve growth factor, and interleukins).

PURPOSE

In this review, we discuss current physiological and pathophysiological aspects of the intestinal barrier and, in particular, its regulation by neuroimmune factors.

Positive interactions with the microbiota: probiotics

Rigorous research in the field of probiotics is a fairly new phenomenon although first reports about beneficial effects of specific gut bacteria on human health originated already a century ago. A prerequisite for such a scrutiny has been a definition of criteria for probiotics. Recently, novel molecular technologies have characterized both potential targets of probiotic action, like gut microbiota and established and candidate probiotic strains in more detail. We thus propose here revised criteria for selection ofprobiotics. In addition to several promising clinical studies e.g., in the prevention and treatment of atopic eczema, certain probiotics have been found to maintain intestinal equilibrium by enhancing the gut mucosal barrier via manipulation of expression of several their own and the host's genes. Introduction of genetic engineering has provided advanced tools to amend probiotics' properties in the fight against different inflammatory conditions.

Intestinal permeability and effects of Lactobacillus rhamnosus therapy in children with short bowel syndrome

BACKGROUND

The present study was conducted to investigate the effects of Lactobacillus rhamnosus (also known as LGG) on intestinal permeability (IP) in children with short bowel syndrome (SBS).

PATIENTS AND METHODS

In a double-blind, placebo-controlled crossover clinical trial, baseline IP (ie, lactulose-to-mannitol ratio) was measured in subjects with SBS and healthy control subjects. Subjects with SBS received LGG or placebo for 4 weeks, followed by a 3-week washout before therapy was crossed over for another 4 weeks. IP, quantitative fecal cultures for Lactobacillus species (in colony-forming units [cfu] per gram of stool) and hydrogen breath test (HBT) were performed during LGG and placebo phases of therapy.

RESULTS

Twenty-one children (SBS, n = 9; control, n = 12) with a median age of 4.5 years (range 1.6-16.4 years) enrolled. Baseline IP measurements were similar in patients with SBS and control subjects: 0.08 +/- 0.06 (mean +/- SD) versus 0.07 +/- 0.05 (P = 1.0). IP was correlated with age in control subjects (r = -0.83, P = 0.001) but not among patients with SBS (r = -0.55, P = 0.16). Fecal colonization with Lactobacillus species did not differ during LGG versus placebo therapy (median 1.4 x 10(9) cfu/g [range 4.0 x 10(5) to 4.0 x 10(9) cfu/g] vs 6.0 x 10(9) cfu/g [1.0 x 10(3) to 1.0 x 10(10) cfu/g], respectively; P = 0.83). LGG therapy had no consistent effects on IP (P = 0.58) or its relationship with age (r = -0.40, P = 0.29), and was associated with conversion to positive HBT results in 1 subject.

CONCLUSIONS

In this sample of children with SBS, the IP was within normal limits but did not correlate with age. LGG therapy had no consistent effects on IP. These findings do not support empiric LGG therapy to enhance IP in children with SBS.

An eye witness perspective of the changing patterns of food allergy

Food allergy may affect the gastrointestinal tract of children and adults too, albeit less commonly. The changing clinico-pathological expression of such food allergy in children over a 30 year period is related, from the eye witness perspective of a paediatric gastroenterologist in London. Tissue diagnosis by biopsy, related to dietary elimination and challenge has been the basis for the first clinico-pathological descriptions and accurate clinical diagnosis of these syndromes as they affect the gastrointestinal tract. In the 1970s cow's milk sensitive enteropathy presenting as chronic diarrhoea and failure to thrive in infancy often after infective gastroenteritis, especially with enteropathogenic Escherichia coli, was an important problem. By the late 1990s such presentations had become most uncommon in developed communities but they continue to occur in developing communities. By contrast in more recent times, multiple food allergy associated with minor small intestinal enteropathy and gastro-oesophageal reflux in older children has become an important clinical problem in children seen in developed communities. Accompanying these changes has been a dramatic fall in the number of children with clinically severe gastroenteritis with severe dehydration requiring hospital admission. Furthermore, the widespread diagnostic use of endoscopy of the upper and lower gastrointestinal tract in children with multiple biopsies has expanded gastroenterological diagnosis in children. This approach gives information about the oesophagus and ileo-colon not available in the earlier studies, which largely concentrated upon small intestinal biopsies, obtained by Crosby capsule biopsy. So, over this 30 year period clinico-pathological expression has altered but also the diagnostic approach has technically changed.