Table 1.

The classification of fatty acids involved in microglial phagocytosis

Fatty acids	Examples	Function	References
Saturated fatty acids	Palmitic acid (16:0) Stearic acid (18:0)	Elevation of IL-1β, TNF-α TLR-4 signaling pathway Translocation of NF-κB in nucleus	(Tracy, Bergqvist et al., 2013 [32]) (Wang, Liu et al., 2012 [32])
Omega-3 fatty acids	α-Linolenic acid (18:3n-3) Docosahexanoic acid (22:6n-3) Eicosapentanoic acid (20:5n-3)	Elevation of TGF-β Increase expression of IKB Inhibition of NF-κB Aβ secretion (downregulate amyloidogenic pathway)	(Hjorth, Zhu et al., 2013 [53]), (De Smedt-Peyrusse, Sargueil et al., 2008 [68]), (Antonietta Ajmone-Cat, Lavinia Salvatori et al., 2012 [69]), (Chen, Zhang et al., 2014 [70]), (Chen, Wu et al., 2017 [71]) (Lim, Calon et al., 2005 [72]), (Oksman, Iivonen et al., 2006 [73])
Omega-6 fatty acid	Arachidonic acid (20:4n-6) Linoleic acid (18:2n-6)	Tau phosphorylation and aggregation Neuroinflammation	(King, Gamblin et al., 2000), (Wilson and Binder 1997 [74])
Omega-6:Omega-3 fatty acids ratio	High omega-6 concentration	Inflammatory response	(Zhu, Wang et al., 2016 [75]), (Lafourcade, Larrieu et al., 2011 [76]), (Thomazeau, Bosch-Bouju et al., 2017 [77]), (Simopoulos 2002 [78])
	High Omega-3 concentration	Anti-inflammatory response