The study of human microbiome is widely perceived to be a young biomedical discipline. Recent studies indicate an association between human microbiome and chronic disease conditions such as diabetes and obesity. An understanding of human microbiome structure and function is important for design and delivery of microbial based therapies especially against immunological and metabolic chronic diseases. In this review, we demonstrate the role human microbiota in health and disease in various anatomic sites and in development of neonate immunity. In particular, the review focuses on the role of placental microbiota in fetoplacental unit receptivity and the effect of early microbiota exposure on neonate immunity development. Additionaly, microbiota impact on health and disease in the gut, lung and skin is explored.Urticaria is a common condition – it is estimated that lifetime incidence of urticaria is approximately 15%, with females being affected more often than males. Both children and adults may develop urticaria, with the peak age of onset in adults being between 20 and 40 years. Urticaria is defined as ‘acute’ if it lasts for less than 6 weeks and ‘chronic’ if it lasts for more than 6 weeks. ‘Episodic’ urticaria, which occurs intermittently, but recurrently over months or years, is also recognized. Most urticarial reactions are acute and self-limiting; however, patients referred to allergy clinics usually have chronic urticaria or episodic urticaria. Histology shows oedema of the upper dermis, dilatation of blood vessels and lymphatics and a cellular infiltrate in the dermis. The nature of this cell infiltrate varies depending on the type of urticaria and the duration of the weal.