*Review* **The Microbiota-Bone-Allergy Interplay**

**Maria Maddalena Sirufo 1,2, Francesca De Pietro 1,2, Alessandra Catalogna 1,2, Lia Ginaldi 1,2 and Massimo De Martinis 1,2,\***

> 1 Department of Life, Health and Environmental Sciences, University of L'Aquila, Piazzale Salvatore Tommasi n. 1, 67100 L'Aquila, Italy; maddalena.sirufo@gmail.com (M.M.S.); fra722@hotmail.it (F.D.P.); alessandra.cat4@gmail.com(A.C.);lia.ginaldi@cc.univaq.it(L.G.)


**Abstract:** Emerging knowledge suggests an increasing importance of gu<sup>t</sup> microbiota in health and disease. Allergy and bone metabolism are closely interconnected, and the possible negative effects of common therapies are not the only aspects of this relationship. The immune system is influenced by the microbiota-host interactions, and several pieces of evidence sugges<sup>t</sup> the existence of an interplay between microbiota, bone metabolism, and allergies. Understanding these interrelationships is essential for the development of new potential strategies of treatment and prevention targeting microbiota. A wide range of substances and germs, prebiotics and probiotics, are capable of influencing and modifying the microbiota. Prebiotics and probiotics have been shown in several studies to have different actions based on various factors such as sex, hormonal status, and age. In this review, we summarize the latest knowledge on the topic, and we discuss practical implications and the need for further studies.

**Keywords:** microbiota; gu<sup>t</sup> microbiota; allergy; osteoporosis; bone metabolism; food allergy; skeletal health; inflammation; osteoimmunology
