Fig. 7From: Emerging trends and hotspot in gut–lung axis research from 2011 to 2021: a bibliometrics analysisTop 25 keywords in burst impact. The blue and white squares in each row on the right side of the figure correspond to the year of hotspot. Red squares represent the year of hotspot, and blue squares represent non-hotspot year. The recent successive red squares represent the research hotspots in recent yearsBack to article page