**1. Introduction**

Eosinophils are well recognised as important drivers of a number of inflammatory diseases in humans, including asthma. Biologic therapies targeting cytokines involved in the activation of eosinophils have been a major advance in the management of eosinophilic asthma [1]; however, for milder forms of asthma, there have been no new additions to the treatment armamentarium for a number of years.

Polyunsaturated fatty acids (PUFAs) contained in the oil fraction of fresh fish provide anti-inflammatory and antioxidant benefits important for the maintenance of good health [2]. Observational and epidemiological studies indicate that regular fish consumption can have wide ranging benefits on human health, including the cardiovascular and respiratory systems. Indeed, changing dietary habits have seen a decline in fish consumption and an increase in the prevalence of asthma and allergic disease in Western countries [3–5]. To compensate for this, dietary supplementation with omega-3 fish oil is frequently used to try to attain the health benefits of consuming fresh fish. Fish oil PUFAs are known to be metabolized into specialized pro-resolving mediators (SPMs), which provide broad inflammation-resolving effects [6]. Whilst trials of omega-3 supplementation suggest a potential to reduce airway inflammation and improve lung function, the effects have been variable [7–10]. However, there is evidence that whole fish consumption during pregnancy and in young children can reduce the risk of developing allergic conditions, a

**Citation:** Currie, C.; Framroze, B.; Singh, D.; Lea, S.; Bjerknes, C.; Hermansen, E. Assessing the Anti-Inflammatory Effects of an Orally Dosed Enzymatically Liberated Fish Oil in a House Dust Model of Allergic Asthma. *Biomedicines* **2022**, *10*, 2574. https://doi.org/10.3390/ biomedicines10102574

Academic Editor: Stanislawa Bazan-Socha

Received: 28 August 2022 Accepted: 11 October 2022 Published: 14 October 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

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benefit likely derived from the range of anti-inflammatory factors naturally contained in fish oil and not just omega-3 [11].

The potential to reduce the burden of asthma via a dietary intervention could be beneficial for sufferers and healthcare systems alike. This trial, therefore, assessed the extent to which oral OmeGo, an intervention more closely related to eating whole fish, could reduce lung inflammation in a standard animal model of induced asthma. OmeGo is minimally processed whole fish oil with low levels of oxidation and free fatty acids and contains all of the polyunsaturated acids found in whole fish, not just omega-3. Previous in vitro work demonstrated OmeGo to significantly reduce eosinophilic effector function, whereas this was not the case for oils containing either omega-3 alone or omega-3 and astaxanthin [12], and a similar comparative profile between OmeGo and omega-3 oils was also demonstrated in animal models of induced eosinophilia [13]. As these previous in vivo studies administered OmeGo by the intraperitoneal route, this paper describes experiments focused now on oral delivery, to provide information that is more relevant to its use in humans. Furthermore, we evaluated lung remodelling as well as inflammation to further assess the potential to improve health outcomes compared to omega-3 supplementation alone [14].
