Quieres $es->innertext
y no $es
.
Prueba este código:
$html =file_get_html('http://www.espncricinfo.com/rankings/content/current/page/211271.html');
$es = $html->find('td[class=left]',37);
$query = "UPDATE my_table SET Column1='".$es->innertext."' WHERE Column2=123;";