*Review* **Cannabinoids and Inflammations of the Gut-Lung-Skin Barrier**

**Cristian Scheau 1 , Constantin Caruntu 1,2 , Ioana Anca Badarau 1 , Andreea-Elena Scheau 3 , Anca Oana Docea 4, \* , Daniela Calina 5, \* and Ana Caruntu 6,7**


**Abstract:** Recent studies have identified great similarities and interferences between the epithelial layers of the digestive tract, the airways and the cutaneous layer. The relationship between these structures seems to implicate signaling pathways, cellular components and metabolic features, and has led to the definition of a gut-lung-skin barrier. Inflammation seems to involve common features in these tissues; therefore, analyzing the similarities and differences in the modulation of its biomarkers can yield significant data promoting a better understanding of the particularities of specific signaling pathways and cellular effects. Cannabinoids are well known for a wide array of beneficial effects, including anti-inflammatory properties. This paper aims to explore the effects of natural and synthetic cannabinoids, including the components of the endocannabinoid system, in relation to the inflammation of the gut-lung-skin barrier epithelia. Recent advancements in the use of cannabinoids as anti-inflammatory substances in various disorders of the gut, lungs and skin are detailed. Some studies have reported mixed or controversial results, and these have also been addressed in our paper.

**Keywords:** cannabinoids; inflammation; gut-lung-skin barrier; signaling pathways; inflammatory biomarkers
