Background and Objectives: Atopic dermatitis (AD) is a chronic inflammatory skin disorder primarily affecting children, driven by genetic, immunologic, and environmental factors. Emerging evidence links gut microbiota alterations to immune modulation and AD severity. Probiotics, live microorganisms providing health benefits when consumed in adequate amounts, have been proposed as a potential adjunctive therapy. This review evaluates the efficacy of various probiotic treatments in reducing SCORAD indices and symptoms in children with AD, and its effects on immunologic markers such as IgE. Materials and Methods: Through a systematic literature review of multiple electronic databases through 9 October 2024, we identified randomized controlled trials (RCTs) in pediatric patients with an established diagnosis of atopic dermatitis. Our search strategy was as follows: “((atopy) OR (dermatitis) OR (hypersensitivity)) AND pediatric AND probiotic” yielding 25 total studies. Patients were treated with either a probiotic regimen or placebo and assessed for levels of IgE and SCORAD indices. Results: Of 25 studies extracted, 14 RCTs evaluated the effects of probiotics on atopic dermatitis using SCORAD scores. Eleven showed significant reductions in SCORAD indices. Pooled analysis using a random-effects model (Hedges’ g ≈ 0.65, p < 0.05) indicated a moderate to large improvement in AD severity with probiotic therapy. However, heterogeneity in probiotic strains, intervention duration, and limited sample sizes are limitations that warrant further investigation. Secondary analysis of IgE changes showed a non-significant effect (g ≈ 0.15, p = 0.13), possibly due to short study durations (mean 12 weeks). Conclusions: Probiotics demonstrate a moderate to large clinical impact in reducing SCORAD indices among children with atopic dermatitis. These findings highlight their potential as a future adjunctive, non-pharmaceutical therapy for the roughly 9.6 million pediatric patients affected in the United States. Further studies are needed to clarify strain-specific effects and patient factors influencing response.

Neurodegenerative diseases (NDDs), including Alzheimer’s Disease (AD), Parkinson’s Disease (PD), and Huntington’s Disease (HD), share pathologic mechanisms including oxidative stress, mitochondrial dysfunction, and protein aggregation. However, they differ in age of onset and clinical progression. Emerging evidence highlights primary cilia (PC) as a key regulator of neuronal aging and the progression of these diseases. Dysfunctional PC may impair key signaling pathways, such as Sonic Hedgehog (Shh) and Wnt, promote oxidative stress, mitochondrial damage, and epigenetic instability. PC may also influence intercellular communication by regulating the biogenesis of exosomes and modulating tunneling nanotube (TNT) formation, both of which propagate toxic proteins between neurons. Mechanistically, the regulation of ciliary length is disrupted in AD, which leads to ciliary dysfunction that interferes with signaling pathways and promotes the aggregation of amyloid-beta. This amyloid-beta is then propagated through TNTs and exosomes, spreading neuronal damage. In PD, the accumulation of alpha-synuclein (α-syn) also impairs cilia function, thereby compromising the cell’s response to oxidative stress. This results in the formation of abnormal TNTs and defective exosome-mediated clearance, ultimately contributing to neurodegeneration. Similarly, the mutant huntingtin protein aggregates within primary cilia in HD, morphologically disrupting them by obstructing intraflagellar transport. Damaged cilia are also associated with increased TNT formation and the exosomal release of toxic proteins, which leads to mitochondrial and epigenetic instability, ultimately promoting neuronal aging. Together, targeting ciliary function and its downstream regulation of TNTs and exosomes may provide a novel approach for slowing or halting disease progression across neurodegenerative diseases.