Intestinal Alkaline Phosphatase Functions in Gut Health and Disease

Intestinal alkaline phosphatase (IAP) is a brush border metalloenzyme expressed along the small intestine that exerts fundamental roles in preserving gut homeostasis and protecting against disease. By dephosphorylating lipopolysaccharide (LPS) and extracellular nucleotides, IAP reduces inflammatory signalling, supports tight junction integrity and curbs endotoxaemia. It also shapes the composition of the gut microbiota through direct detoxification of microbial components and indirect modulation of luminal phosphate availability. Impaired IAP activity has been linked to gastrointestinal disorders such as inflammatory bowel disease, necrotising enterocolitis and metabolic syndrome, as well as systemic conditions including ageing-related frailty and liver fibrosis. Conversely, exogenous supplementation or upregulation of endogenous IAP activity has shown promise in restoring barrier function, attenuating inflammation and promoting microbial balance, underscoring its potential as a therapeutic target in gut-related pathologies.

Research from Nature Portfolio

Recent studies have demonstrated that IAP induces autophagy to mediate its anti-inflammatory effects. Administration of exogenous IAP in intestinal epithelial cells and macrophages was found to stimulate key autophagy markers and inhibit NF-κB activation in response to LPS. In vivo experiments revealed that oral IAP supplementation upregulates autophagy-related genes and increases LC3 expression in the ileum of treated mice, linking enhanced autophagic flux to reduced proinflammatory cytokine production. These findings provide a mechanistic basis for the protective role of IAP in controlling gut inflammation through coordination of barrier function, microbial detoxification and intracellular quality control pathways.

Intestinal Alkaline Phosphatase Functions in Gut Health and Disease publication trend

The graph below shows the total number of articles in intestinal alkaline phosphatase functions in gut health and disease across all publications each year (not limited to Nature Index journals).

Technical terms

Intestinal alkaline phosphatase (IAP): A metalloenzyme anchored to the brush border of enterocytes that dephosphorylates microbial and host molecules to reduce inflammation and support barrier function.

Lipopolysaccharide (LPS): A component of Gram-negative bacterial cell walls that triggers inflammatory responses via Toll-like receptor 4.

Autophagy: A conserved cellular process for recycling damaged organelles and proteins, which can modulate inflammation and cell survival.

Gut microbiota: The diverse community of microorganisms residing in the gastrointestinal tract that influences host nutrition, immunity and metabolism.

Tight junction proteins: Transmembrane and scaffold proteins (for example, occludin and claudins) that seal the paracellular space between epithelial cells to maintain barrier integrity.

Endotoxaemia: The entry of bacterial endotoxins into the circulation due to impaired gut barrier, leading to systemic inflammation.

References

1. Intestinal Alkaline Phosphatase Exerts Anti-Inflammatory Effects Against Lipopolysaccharide by Inducing Autophagy. Scientific Reports (2020).
2. A role for intestinal alkaline phosphatase in preventing liver fibrosis. Theranostics (2021).
3. Intestinal alkaline phosphatase targets the gut barrier to prevent aging. JCI Insight (2020).
4. Alkaline Phosphatase Relieves Colitis in Obese Mice Subjected to Forced Exercise via Its Anti-Inflammatory and Intestinal Microbiota-Shaping Properties. International Journal of Molecular Sciences (2024).
5. Intestinal Alkaline Phosphatase: A Review of This Enzyme Role in the Intestinal Barrier Function. Microorganisms (2022).